Open Versus Arthroscopic Mosaicplasty of the Knee: A Cadaveric Assessment of Accuracy of Graft Placement Using Navigation

Surface morphology of osteochondral grafts harvested from femoral condyles with free-hand technique: a cadaveric study

PURPOSE

The purpose of this cadaver study was to examine the surface morphology of the osteochondral grafts harvested from the femoral condyles using the free-hand graft harvesting technique.

MATERIALS AND METHODS

One hundred osteochondral grafts were harvested with 6.5 mm chisels at ten different donor sites using the free-hand technique in five paired knee specimens (Mean age: 56.4 years). The cartilage and subchondral bone surface angles were measured through multiplanar reconstruction computerized tomography examination. The cartilage thickness was measured with a MicroScribe G2X digitizer with an accuracy of 0.02 mm. An acceptable congruity could be obtained when these plugs were transferred to a perpendicular socket (articular step-off of less than 1 mm and 0.5 mm) was evaluated.

RESULTS

Four plugs were damaged or broken during harvesting due to technical difficulties; thus remaining 96 plugs were analyzed. The cartilage thickness varied between 1.36 mm and 3.26 mm across the donor sites. The cartilage was the thinnest in the medial intercondylar notch and thickest in the lateral supracondylar notch. Twenty of ninety-six plugs (20.8%) had unacceptable cartilage surface inclination according to the > 0.5 mm protrusion criteria. Of these plugs, 14 were harvested from the lateral intercondylar notch, whereas five of 96 plugs (5.2%) had unacceptable cartilage surface inclination according to the > 1 mm protrusion criteria. Of these plugs, all were harvested from the lateral intercondylar notch.

CONCLUSIONS

High rates of unacceptable plugs (up to 100%) might be harvested from the lateral intercondylar notch. In large chondral lesions that require multiple plugs, lateral and medial supracondylar ridges were the best donor sites for perpendicular plug harvesting, whereas lateral intercondylar notch should be avoided.

ArthroNavi framework: stereo endoscope-guided instrument localization for arthroscopic minimally invasive surgeries

Significance

As an example of a minimally invasive arthroscopic surgical procedure, arthroscopic osteochondral autograft transplantation (OAT) is a common option for repairing focal cartilage defects in the knee joints. Arthroscopic OAT offers considerable benefits to patients, such as less post-operative pain and shorter hospital stays. However, performing OAT arthroscopically is an extremely demanding task because the osteochondral graft harvester must remain perpendicular to the cartilage surface to avoid differences in angulation.

Aim

We present a practical ArthroNavi framework for instrument pose localization by combining a self-developed stereo endoscopy with electromagnetic computation, which equips surgeons with surgical navigation assistance that eases the operational constraints of arthroscopic OAT surgery.

Approach

A prototype of a stereo endoscope specifically fit for a texture-less scene is introduced extensively. Then, the proposed framework employs the semi-global matching algorithm integrating the matching cubes method for real-time processing of the 3D point cloud. To address issues regarding initialization and occlusion, a displaying method based on patient tracking coordinates is proposed for intra-operative robust navigation. A geometrical constraint method that utilizes the 3D point cloud is used to compute a pose for the instrument. Finally, a hemisphere tabulation method is presented for pose accuracy evaluation.

Results

Experimental results show that our endoscope achieves 3D shape measurement with an accuracy of < 730    μ m . The mean error of pose localization is 15.4 deg (range of 10.3 deg to 21.3 deg; standard deviation of 3.08 deg) in our ArthroNavi method, which is within the same order of magnitude as that achieved by experienced surgeons using a freehand technique.

Conclusions

The effectiveness of the proposed ArthroNavi has been validated on a phantom femur. The potential contribution of this framework may provide a new computer-aided option for arthroscopic OAT surgery.

Arthroscopic Osteochondral Autograft Transfer System Procedure of the Lateral Femoral Condyle with Donor-Site Backfill Using Osteochondral Allograft Plug

The osteochondral autograft transfer system (OATS) procedure is at the forefront of cartilage restoration surgeries of the knee, offering superior return to sport rates and long-term functionality. This technique reports an arthroscopic OATS procedure of the lateral femoral condyle with donor-site backfill using an osteochondral allograft plug. Potential complications from unfilled donor site sockets are eliminated through donor site backfill with an allograft plug.

Arthroscopic versus Open Osteochondral Autograft Transplantation (Mosaicplasty) for Cartilage Damage of the Knee: A Systematic Review

Osteochondral autograft transplantation (OAT) is a surgical option for repairing cartilage damage in knees, and can be performed using open or arthroscopic procedures. The aim of this review was to report clinical outcomes, postoperative complications, defect location, and defect size between open and arthroscopic OATs. Three electronic databases (EMBASE, PUBMED, and MEDLINE) were searched for relevant articles. In regard to eligibility criteria, knee articular damage cases solely treated with OAT were included and cases concomitant with ligament reconstruction, limb realignment, and meniscus repair were excluded. The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) and descriptive statistics are presented. A total of 24 studies were included with a total sample of 1,139 patients (532 in open OAT vs. 607 in arthroscopic OAT). Defect size in open OAT was three times larger than that of arthroscopic OAT (2.96 ± 0.76 vs. 0.97 ± 0.48 cm²). In terms of defect location, the medial femoral condyle (MFC) was the most common (75.4%), followed by the lateral femoral condyle (LFC; 12.1%), patella (6.7%), and trochlea (5.7%). All of these defect locations were treated with open OAT, whereas arthroscopic OAT treatments were restricted to the MFC and LFC. The clinical outcomes were overall favorable with the modified Hospital for Special Surgery knee scores being 89.6 ± 8.0 (36.1-month follow-up) versus 90.4 ± 6.0 (89.5-month follow-up) and the Lysholm scores being 81.6 ± 8.9 (44.2-month follow-up) and 83.3 ± 7.4 (12.0-month follow-up) between open and arthroscopic OATs, respectively. Fifty-three postoperative complications were observed (39/279 vs. 14/594) and the most common complication was hemarthrosis (13/39 in open, vs. 1/14 in arthroscopic OAT). The overall clinical outcomes were favorable in open and arthroscopic OATs, whereas open OAT allowed for treatment of lesions approximately three times greater in dimension than in arthroscopic OAT. Also, defect location was restricted to MFC and LFC in arthroscopic OAT. The most common complication was hemarthrosis.

Osteochondral Autograft Transfer Procedure: Arthroscopic Technique and Technical Pearls

The Osteochondral Autograft Transfer System (OATS; Arthrex, Naples, FL) is an excellent option for the treatment of articular cartilage lesions within the knee. Current literature suggests that at early-term to midterm follow-up, patients experience improved function, alleviation of pain, and good satisfaction with acceptable complication rates. Although long-term data are lacking, studies in athletes have shown that the OATS can provide an adequate rate of return to sports. The OATS procedure has traditionally been considered an open procedure. However, with the advancement of arthroscopic techniques, the procedure can now be completed arthroscopically. We discuss this modern operation.