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

Biomechanical properties of articular cartilage in different regions and sites of the knee joint: acquisition of osteochondral allografts

Osteochondral allograft (OCA) transplantation involves grafting of natural hyaline cartilage and supporting subchondral bone into the cartilage defect area to restore its biomechanical and tissue structure. However, differences in biomechanical properties and donor-host matching may impair the integration of articular cartilage (AC). This study analyzed the biomechanical properties of the AC in different regions of different sites of the knee joint and provided a novel approach to OCA transplantation. Intact stifle joints from skeletally mature pigs were collected from a local abattoir less than 8 h after slaughter. OCAs were collected from different regions of the joints. The patella and the tibial plateau were divided into medial and lateral regions, while the trochlea and femoral condyle were divided into six regions. The OCAs were analyzed and compared for Young's modulus, the compressive modulus, and cartilage thickness. Young's modulus, cartilage thickness, and compressive modulus of OCA were significantly different in different regions of the joints. A negative correlation was observed between Young's modulus and the proportion of the subchondral bone (r =  - 0.4241, P < 0.0001). Cartilage thickness was positively correlated with Young's modulus (r = 0.4473, P < 0.0001) and the compressive modulus (r = 0.3678, P < 0.0001). During OCA transplantation, OCAs should be transplanted in the same regions, or at the closest possible regions to maintain consistency of the biomechanical properties and cartilage thickness of the donor and recipient, to ensure smooth integration with the surrounding tissue. A 7 mm depth achieved a higher Young's modulus, and may represent the ideal length.

Return to Duty in Military Servicemembers After High Tibial Osteotomy Not Associated With Preoperative Radiographic Parameters : A Retrospective Analysis

Background

Evidence on return to sports/work after high tibial osteotomy (HTO) is limited, especially in a young, high-demand population.

Purpose

To (1) identify whether preoperative knee pathology or intraoperative correction was associated with successful return to duty (RTD) and (2) assess whether postoperative complications and reoperation were associated with failure to RTD.

Study Design

Case series; Level of Evidence, 4.

Methods

We performed a retrospective cohort study of a consecutive series of patients in the Military Health System aged 18 to 55 years with medial compartment osteoarthritis who underwent HTO between 2003 and 2018. Concomitant meniscal and cartilage procedures were included, while cases with concomitant ligamentous procedures were excluded. The inclusion criteria were as follows: active-duty military status, minimum 2-year follow-up, preoperative knee radiographs, and pre- and postoperative long-leg alignment radiographs. Preoperative Kellgren-Lawrence grades and pre- and postoperative hip-knee-ankle angles were measured. The primary outcome was RTD. Failure was defined as knee-related medical separation from the military or conversion to total knee arthroplasty. The secondary outcome was reoperation.

Results

A total of 55 HTOs were performed in 50 patients who met the inclusion criteria, with a mean age of 39 years old (range, 22.8-55 years). The mean follow-up was 5 years (range, 2.1-10.7 years). Ten knees (18.2%) failed HTO (1 conversion to total knee arthroplasty, 9 medical separations), 15 additional knees (27.3%) had permanent activity restrictions, and 30 knees (54.5%) returned to duty without restrictions. Reoperation occurred in 36.4% of knees and was associated with medical separation (P = .039). Younger age was associated with medical separation (P = .003) and permanent restrictions (P = .006). Patients with a postoperative varus deformity of >5° were more likely to undergo medical separation (P = .023).

Conclusion

In a young, high-demand population, HTO succeeded in returning 54.5% of knees to full duty without restriction despite 36.4% of knees requiring reoperation. Residual varus deformity or reoperation was associated with lower RTD rates. No association was identified between RTD and preoperative osteoarthritis grading or deformity.

High-Speed Centrifugation Efficiently Removes Immunogenic Elements in Osteochondral Allografts

OBJECTIVES

The current clinical pulse lavage technique for flushing fresh osteochondral allografts (OCAs) to remove immunogenic elements from the subchondral bone is ineffective. This study aimed to identify the optimal method for removing immunogenic elements from OCAs.

METHODS

We examined five methods for the physical removal of immunogenic elements from OCAs from the femoral condyle of porcine knees. We distributed the OCAs randomly into the following seven groups: (1) control, (2) saline, (3) ultrasound, (4) vortex vibration (VV), (5) low-pulse lavage (LPL), (6) high-pulse lavage (HPL), and (7) high-speed centrifugation (HSC). OCAs were evaluated using weight measurement, micro-computed tomography (micro-CT), macroscopic and histological evaluation, DNA quantification, and chondrocyte activity testing. Additionally, the subchondral bone was zoned to assess the bone marrow and nucleated cell contents. One-way ANOVA and paired two-tailed Student's t-test are used for statistical analysis.

RESULTS

Histological evaluation and DNA quantification showed no significant reduction in marrow elements compared to the control group after the OCAs were treated with saline, ultrasound, or VV treatments; however, there was a significant reduction in marrow elements after LPL, HPL, and HSC treatments. Furthermore, HSC more effectively reduced the marrow elements of OCAs in the middle and deep zones compared with LPL (p < 0.0001) and HPL (p < 0.0001). Macroscopic evaluation revealed a significant reduction in blood, lipid, and marrow elements in the subchondral bone after HSC. Micro-CT, histological analyses, and chondrocyte viability results showed that HSC did not damage the subchondral bone and cartilage; however, LPL and HPL may damage the subchondral bone.

CONCLUSION

HSC may play an important role in decreasing immunogenicity and therefore potentially increasing the success of OCA transplantation.

Increased Host Bone Marrow Edema on 6-Month MRI Is a Risk Factor for Osteochondral Allograft Failure

PURPOSE

To evaluate the presence of host bone marrow edema (BME) surrounding osteochondral allograft (OCA) plugs on routine 6-month postoperative magnetic resonance imaging (MRI) and to determine whether such BME is correlated with subsequent failure.

METHODS

The present study was approved under our institutional review board-approved database (#2020-2123). We included patients who underwent cartilage repair with OCA for focal chondral and osteochondral defects of the distal femur by 2 senior surgeons between January 2016 and May 2021 with minimum 2-year follow-up. OCA is frequently performed with concomitant procedures, and therefore ligament reconstruction, meniscal surgery, and osteotomy were not exclusion criteria. Failure was defined as (1) poor clinical outcome with graft collapse on follow-up MRI or second-look arthroscopy, (2) primary OCA removal or revision, or (3) conversion to unicompartmental or total knee arthroplasty. Routine MRI scans were performed at 6 ± 2 months postoperatively. All postoperative MRI scans were reviewed from our imaging record by 2 blinded fellowship-trained orthopaedic surgeons. Patients were divided for analyses into 2 groups: BME ≥10 cm3 versus BME <10 cm3.

RESULTS

Of the 85 patients eligible for the study, 56 patients (30 female, mean age 31.69 ± 11.34 years) had a minimum 2-year follow-up. Nonfailure cases had a mean clinical follow-up of 3.13 ± 0.93 years. The mean time from surgery to failure in our cohort was 1.67 ± 0.91 years. There were 12 (21.4%) patients with BME ≥10 cm³ and 44 (78.6%) patients with BME <10 cm³. No statistically significant differences were found between groups when compared for sex, age, body mass index, OCA size, time to MRI, mean follow-up, number of plugs, graft location, diagnosis, previous surgeries, or concomitant procedures. All OCA failures of the study cohort were in the BME ≥10 cm³ group, representing 50% of this group (P < .001). Kaplan-Meier survival analysis with the log-rank test demonstrated significant difference in survival distributions between groups (P < .001). Patients who ultimately failed had a mean BME volume of 18.49 ± 5.82 cm3, while the nonfailure group had a mean volume of 4.66 ± 4.97 cm3 (P < .001). Cutoff values around 10 cm³ in receiver operating characteristic curve analysis demonstrated 100% sensitivity and close to 90% specificity for OCA failure diagnosis.

CONCLUSION

Host BME with a volume greater than 10 cm³ on 6-month postoperative MRI is predictive of an increased subsequent failure rate after OCA transplantation with a failure rate of 50%.

LEVEL OF EVIDENCE

Level III, cohort study.

Characteristics and Clinical Outcomes After Osteochondral Allograft Transplantation for Treating Articular Cartilage Defects: Systematic Review and Single-Arm Meta-analysis of Studies From 2001 to 2020

Background

Osteochondral allograft transplantation (OCA) treats symptomatic focal cartilage defects with satisfactory clinical results.

Purpose

To comprehensively analyze the characteristics and clinical outcomes of OCA for treating articular cartilage defects.

Study Design

Systematic review; Level of evidence, 4.

Methods

We searched Embase, PubMed, Cochrane Database, and Web of Science for studies published between January 1, 2001, and December 31, 2020, on OCA for treating articular cartilage defects. Publication information, patient data, osteochondral allograft storage details, and clinical outcomes were extracted to conduct a comprehensive summative analysis.

Results

In total, 105 studies involving 5952 patients were included. The annual reported number of patients treated with OCA increased from 69 in 2001 to 1065 in 2020, peaking at 1504 cases in 2018. Most studies (90.1%) were performed in the United States. The mean age at surgery was 34.2 years, and 60.8% of patients were male and had a mean body mass index of 26.7 kg/m2. The mean lesion area was 5.05 cm2, the mean follow-up duration was 54.39 months, the mean graft size was 6.85 cm2, and the number of grafts per patient was 54.7. The failure rate after OCA was 18.8%, and 83.1% of patients reported satisfactory results. Allograft survival rates at 2, 5, 10, 15, 20, and 25 years were 94%, 87.9%, 80%, 73%, 55%, and 59.4%, respectively. OCA was mainly performed on the knee (88.9%). The most common diagnosis in the knee was osteochondritis dissecans (37.9%), and the most common defect location was the medial femoral condyle (52%). The most common concomitant procedures were high tibial osteotomy (28.4%) and meniscal allograft transplantation (24.7%). After OCA failure, 54.7% of patients underwent revision with primary total knee arthroplasty.

Conclusion

The annual reported number of patients who underwent OCA showed a significant upward trend, especially from 2016 to 2020. Patients receiving OCA were predominantly young male adults with a high body mass index. OCA was more established for knee cartilage than an injury at other sites, and its best indication was osteochondritis dissecans. This analysis demonstrated satisfactory long-term postoperative outcomes.

Management Considerations for Unicompartmental Osteoarthritis in Athletic Populations: A Review of the Literature

Unicompartmental osteoarthritis in the young athlete poses a challenge for both patients and providers. Coronal plane malalignment is frequently a concomitant finding that adds to the complexity of management. Military surgeons are presented unique challenges, in that they must consider optimal joint-preservation methods while returning patients to a high-demand occupational function. Management options range from lifestyle changes to surgical interventions. We present a concise review of the available literature on this subject, with a specific focus on indications and outcomes within the military and young athletic population.

Treatment of Malalignment and Cartilage Injury: High Tibial Osteotomy With a Concomitant Osteochondral Allograft to the Medial Femoral Condyle and Lateral and Medial Partial Meniscectomy

In patients with full-thickness focal cartilage defects, osteochondral allograft is a technique for restoration of hyaline cartilage; however, in patients with genu varum, the diseased compartment of the knee is generally offloaded as well. A high tibial osteotomy presents a biomechanical solution to malalignment of the knee and offloading of the diseased compartment of the knee. The purpose of this Technical Note is to present our preferred technique to treat focal cartilage damage in a varus misaligned knee coupling a high tibial osteotomy with an osteochondral allograft to the medial femoral condyle, along with partial medial and lateral meniscectomy.

Return to Sport Following Distal Triceps Repair

PURPOSE

The purpose of this investigation was to examine the timeline of return-to-sport following distal triceps repair; evaluate the degree of participation and function upon returning to sport; and identify risk factors for failure to return to sport.

METHODS

Patients who underwent distal triceps repair with a minimum of 1 year of follow-up were retrospectively reviewed. Patients completed a subjective sports questionnaire and were scored on a visual analog scale for pain; the Mayo Elbow Performance Index; the Quick Disabilities of the Arm, Shoulder, and Hand; and the Single Assessment Numerical Evaluation.

RESULTS

Out of 113 eligible patients who had a distal triceps repair, 81 patients (71.7%) were contacted. Sixty-eight patients (84.0%) who participated in sports prior to surgery were included at 6.0 ± 4.0 years after surgery, and the average age was 46.6 ± 11.5 years. Sixty-one patients (89.7%) resumed playing at least 1 sport by 5.9 ± 4.4 months following distal triceps repair. However, 18 patients (29.5%) returned to a lower level of activity intensity. The average postoperative Quick Disabilities of the Arm, Shoulder, and Hand; Mayo Elbow Performance; visual analog scale for pain; and Single Assessment Numerical Evaluation scores were 8.2 ± 14.0, 89.5 ± 13.4, 2.0 ± 1.7, and 82.2 ± 24.3, respectively. No patients underwent revision surgery at the time of final follow-up.

CONCLUSIONS

Distal triceps repair enables 89.7% of patients to return to sport by 5.9 ± 4.4 months following surgery. However, 29.5% of patients were unable to return to their preinjury level of activity. It is imperative that patients are appropriately educated to manage postoperative expectations regarding sport participation following distal triceps repair.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

High Tibial Osteotomies for the Treatment of Osteoarthritis of the Knee

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A high tibial osteotomy (HTO) is a joint-preserving procedure that can be used to treat symptomatic unicompartmental cartilage disorders in the presence of limb malalignment.

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Appropriate patient selection and careful preoperative planning are vital for optimizing outcomes.

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Based on past literature, correction of varus malalignment to 3° to 8° of valgus appears to lead to favorable results. Recently, there has been growing awareness that it is important to consider soft-tissue laxity during preoperative planning.

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Although there has been a recent trend toward performing opening-wedge rather than closing-wedge or dome HTOs for unicompartmental osteoarthritis, current data suggest that all 3 are acceptable techniques with varying complication profiles.

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Based on current evidence, an HTO provides pain relief, functional improvement, and a high rate of return to sport, with reported survivorship ranging from 74.7% to 97.6% and 66.0% to 90.4% at 10 and 15 years, respectively.

Reinforcement strategy for medial open-wedge high tibial osteotomy: a finite element evaluation of the additional opposite screw technique and bone grafts

BACKGROUND AND OBJECTIVE

bone grafts (bgs) and the opposite screw insertion technique are reported to enhance initial stability after medial open-wedge high tibial osteotomy (OWHTO); however, it is unclear how the general and local biomechanical stability of the proximal tibia is affected by these reinforcement strategies. In this study, we aimed to assess the biomechanical differences among different fixation configurations for OWHTO under two loading conditions using finite element analysis, and to assess the biomechanical contribution of an opposite screw insertion.

METHODS

Models of the proximal tibia with three different gap defects were created to simulate different distraction heights in OWHTO. Four groups of models were then assembled with different fixation configurations, including the no BG (NBG) group, BG group, partially threaded screw (PT) group, and fully threaded screw (FT) group. Testing loads were applied to simulate the static forces on the knee joint during double-limb and single-limb standing. For each group, the stresses of the lateral hinge area (LHA) and the medial implant area (MIA), the maximum displacement of the tibia and the relative displacement (RD) of the medial gap were evaluated.

RESULTS

Compared to NBG group, bone block grafting effectively reduced the stress of the tibia and implant, as well as the maximum displacement of the tibia and the RD of the medial gap. The opposite screw group showed similar trends in alleviating the stress concentration on the LHA and MIA, and contributing to the maintaining the medial gap reduction, especially in the FT group; however, additional stresses were concentrated on the opposite screw itself, which indicated the potential risk of screw breakage.

CONCLUSIONS

Compared to NBG group, the BG group bone graft showed superior biomechanical advantages in decreasing the risk of implant failure and lateral hinge fracture, and maintaining the reduction in OWHTO. The additional opposite screw provided an extra support to the proximal tibia, with similar contributions to improve the structural stability after osteotomy, especially in the FT group.

High Tibial Osteotomy for Varus Deformity of the Knee

High tibial osteotomy is a powerful technique to treat symptomatic varus deformity of the knee and is successful when properly indicated and performed. Indications include varus deformity with medial compartment osteoarthritis, cartilage or meniscus pathology. Several techniques exist to correct symptomatic varus malalignment along with concomitant procedures to restore cartilage or meniscus injuries. Evidence supporting high tibial osteotomy for symptomatic medial compartment pathology exists, which provides a durable solution for joint preservation. This review will discuss the indications, techniques, and outcomes for high tibial osteotomies used in the treatment of symptomatic varus deformity of the knee.

Recent Developed Strategies for Enhancing Chondrogenic Differentiation of MSC: Impact on MSC-Based Therapy for Cartilage Regeneration

Articular cartilage is susceptible to damage, but its self-repair is hindered by its avascular nature. Traditional treatment methods are not able to achieve satisfactory repair effects, and the development of tissue engineering techniques has shed new light on cartilage regeneration. Mesenchymal stem cells (MSCs) are one of the most commonly used seed cells in cartilage tissue engineering. However, MSCs tend to lose their multipotency, and the composition and structure of cartilage-like tissues formed by MSCs are far from those of native cartilage. Thus, there is an urgent need to develop strategies that promote MSC chondrogenic differentiation to give rise to durable and phenotypically correct regenerated cartilage. This review provides an overview of recent advances in enhancement strategies for MSC chondrogenic differentiation, including optimization of bioactive factors, culture conditions, cell type selection, coculture, gene editing, scaffolds, and physical stimulation. This review will aid the further understanding of the MSC chondrogenic differentiation process and enable improvement of MSC-based cartilage tissue engineering.