The management of articular cartilage injuries in the

1 2 3 4 5 6 7 8 Q1 Osteochondral Allograft Transplantation and Osteochondral Autograft Transfer D12XXAustin V. Stone, D13XXMD, PhD, D14XXDavid R. Christian, D15XXBS, D16XXMichael L. Redondo, D17XXMA, BS, D18XXAdam B. Yanke, D19XXMD, PhD, and D20XXBrian J. Cole, D21XXMD, MBA 55 56 57 58 59 60 61 62 9 10 11 12 13 14 15 16 17 18 19 Q2 Cartilage defects commonly occur in young, active patients and can be debilitating injuries with patients experiencing significant pain and swelling. Clinical diagnosis is made using a combination of patient history, physical exam, imaging, and diagnostic arthroscopy. In patients who have failed conservative measures such as physical therapy, tolerable lifestyle modification, and injection treatments, surgical options exist including microfracture, autologous chondrocyte implantation, osteochondral autograft transfer, or osteochondral allograft transplantation. In this article, we present the diagnosis, indications, surgical technique, and reported outcomes for the treatment of cartilage defects with both osteochondral autograft transfer and osteochondral allograft transplantation. XX Oper Tech Sports Med &:&&&-&&& 2018 Published by Elsevier Inc. 63 64 65 66 67 68 69 70 71 72 73 20 74 21 75 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 Overview The management of articular cartilage injuries in the active patient can present a challenging problem; however, with proper indications, patient selection, and technical expertise, these patients may have substantial increases in function and satisfaction and a high rate of return to activity. Patients should have specific intraarticular symptoms, be of a relatively normal body mass index (BMI) and have neutral alignment. Radiographic and arthroscopically confirmed pathology should align with the patient s symptoms and exam. The articular cartilage lesion size and location will influence the treatment strategy and concomitant pathology simultaneously addressed. History, Exam, Imaging Patients with cartilage defects typically present with a history of prior knee injury and or surgery. Localized knee pain and joint swelling are common symptoms which are often exacerbated by physical activity. Patients may report mechanical symptoms including catching, locking, and giving way. On physical examination, patients typically have preserved range of motion and an effusion is often observed. The Rush University Medical Center, Chicago, IL. Address reprint requests to Brian J. Cole, MD, MBA, 1611 W. Harrison St., Ste 300, Chicago, IL 60612. E-mail: bcole@rushortho.com affected compartment is typically tender to palpation there may be catching or accreditation in the affected compartment. Quadriceps atrophy is typically seen secondary to the chronicity of the pathology. Loose bodies from chondral fragments are not uncommon and may be associated with locking or limited range of motion. Current imaging practices include weight bearing radiographs. We obtain a weight bearing anteroposterior, lateral, and skiers or notch view of the knee (Fig. 1). A sunrise view is obtained to evaluate patellofemoral joint. We also obtain bilateral long leg alignment radiographs to evaluate the mechanical axis for any varus or valgus deformity that may be predispose the patient to chondral damage (Fig. 1). Recent knee magnetic resonance imaging D2XX is imperative for preoperative planning. T2 weighted magnetic resonance imagingd23xxprovides the best method of preoperatively estimating the defect size and evaluating the subchondral bone for edema or possible cysts which may require bone grafting (Fig. 2). The authors prefer to treat the cartilage lesions in a staged fashion to accurately assess the degree of pathology and lesion dimensions after diagnostic arthroscopy and debridement (Fig. 3). Some patients improve following debridement and may become at least temporarily asymptomatic. 1 If an outside surgeon has recently performed a knee arthroscopy or previously treated the cartilage defect, the operative report, and intraoperative arthroscopic photographs should be obtained for preoperative planning. 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 52 106 53 54 https://doi.org/10.1053/j.otsm.2018.06.007 1060-1872/ 2018 Published by Elsevier Inc. 1 107 108

2 A.V. Stone et al. 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 Figure 1 PreD1XXoperative radiographs. (A) Representative standing weight-bearing radiograph to evaluate sagittal alignment demonstrating varus deformity predisposing the patient to medial compartment osteochondral pathology. (B) Representative anteroposterior standing radiograph of bilateral knees showing a potential osteochondral lesion of the right medial femoral condyle. (C) Lateral radiograph of the right knee. Figure 2 PreD2XXoperative magnetic resonance imaging right knee. T2 weighted sagittal (A) and coronal (B) MRI images depicting a focal chondral defect of the posterior lateral femoral condyle with subchondral edema. (C) T2 weighted axial MRI image depicting a focal chondral defect of the medial patellar facet. 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224

Q3 XXOsteochondral Allograft Transplantation and Osteochondral Autograft Transfer 3 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 Figure 3 IntraD3XXoperative Findings. (A) Arthroscopic images of ICRS Grade III/IV focal chondral defects of the right (A) lateral femoral condyle, (B) central trochlea, and C) patella. Osteochondral Autograft Indications The initial treatment strategy for chondral defects includes rest, oral nonsteroidal anti-inflammatory drugsd24xx, and injection with cortisone and/or hyaluronic acid. Physical therapy prior to surgical intervention may also be considered. For patients with refractory symptoms, osteochondral autograft transfer (OAT) may be considered for those patients with higher demands and an articular cartilage lesion less than 2-3 cm 2. Patients should have neutral alignment and a relatively normal BMI. Surgical Technique The patient should be positioned supine for knee arthroscopy. A standard leg holder may be used with the foot of the bed dropped to allow greater flexibility in accessing the lesions on the posterior femoral condyle. A tourniquet is used to improve visualization. Diagnostic arthroscopy is performed through standard anterolateral and anteromedial portals. Trajectories for plug harvest can be confirmed arthroscopically with spinal needle localization to plan for the most efficient harvest and placement incisions. The senior author (B.J.C.) prefers to harvest through a small incision and implant arthroscopically. A small superolateral incision is made and D25XX2 retractors are used to expose the superolateral trochlea. The lateral trochlea offers the advantages of low contact forces, a convex curvature to match recipient sites, and relatively easy access through limited incisions. Additional sources of osteochondral donor plugs include the superomedial trochlea and superolateral notch. The contralateral knee could also be considered but is generally avoided. Once the lesion has been assessed with diagnostic arthroscopy and concomitant pathology addressed, the osteochondral autograft plug can be harvested. We prefer to use the OATS transport system (Arthrex Inc., Naples, FL). A superolateral incision is used to expose the lateral trochlea. An assembled tube extractor is selected based on the lesion size. The harvester is placed perpendicular to the articular surface and mallet used to advance it to a depth of 10-15 mm. The harvester is rotated 90 clockwise and the plug extracted. The plug is removed and inspected. The plug depth is measured to match the recipient site and placed into the recipient site. The graft may be implanted in an open or arthroscopic fashion, but accurate placement without graft prominence is imperative. The surgical incisions are then closed in a layered fashion. Osteochondral Allograft Indications Osteochondral allograft transplantation (OCA) in the knee may be used to treat a variety of disorders including osteochondral defects, malignant disease, or abnormal development. 2-5 OCA was traditionally used to treat chondral defects arising from osteochondritis dissecans or other traumatic cartilage defects after unsuccessful treatment with techniques such as microfracture, mosaicplasty, and autologous chondrocyte implantation (ACI). Cartilage lesions which have not demonstrated success with these techniques in the past are now increasingly being treated with primary OCA. Candidates for OCA have full thickness chondral or osteochondral defects. Larger lesions that are not full-thickness may also be considered due to the size that precludes other cartilage repair or restoration techniques. Focal unipolar defects larger than 2D26XX -3 cm 2 are ideal candidates for OCA. Modifiable comorbidities and concomitant pathologies should be addressed prior to or during OCA including correction of limb malalignment, ligament deficiency, and meniscal deficiency. Bipolar disease is a relative contraindication due to inferior outcomes, although the techniques are evolving. The need for multiple osteochondral allografts for multifocal chondral disease is not contraindicated. 3 Ideally, the patient s body mass index should be less than 30 kg/m 2. Surgical Technique The patient is placed supine on a standard operating table with a tourniquet placed on the most proximal thigh. The foot of the bed can be lowered when treating femoral condyle lesions to allow better exposure of the posterior condyles. 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340

4 A.V. Stone et al. 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 The leg is exsanguinated and tourniquet inflated to allow increased visualization. We prefer to first perform a diagnostic arthroscopy to address any additional or interval pathology prior to the allograft transplant. A medial or lateral parapatellar arthrotomy incision is used to expose the defect on the respective femoral condyle (Fig. 4A). The exposure may be enhanced with retractors placed in the medial or lateral gutter and in the femoralnotch.forpatellofemorallesions,amedialparapatellar arthrotomy is utilized. The patella can be everted to expose the articular surface or retracted to expose the femoral trochlea. A cannulated sizing cylinder (Arthrex Inc., Naples, FL) is used to assess defect size (Fig. 4B). The cylinder is centered on the cartilage defect and a guide pin is drilled perpendicularly to the lesion (Fig. 4B). The sizing cylinder is removed and a cannulated reamer is passed over the guide pin and reamed to adepthof6-8mm(fig. 4C, D). The reamer may damage the soft tissue or patellar cartilage if not properly protected and should be monitored during drilling. After reaming, the 12 o clock position is marked on the recipient site. A no. 15 scalpel is used to sharply debride the recipient site to clean edges as needed. A ruler is used to measure the depth of the recipient site at 12-, 3-, 6-, and 9-o clock positions in order to accurately prepare the donor osteochondral plug (Fig. 4E). A Kirshner wire or small drill can be used to create vascular channels in the base of the recipient site. The recipient site is then thoroughly irrigated with antibiotic infused saline to remove any osseous or chondral fragments. The osteochondral allograft plug is fashioned from a femoral hemicondyle allograft. The hemicondyle is trimmed with a powersaw as needed to securely fit it into the allograft workstation. An appropriate radius of curvature is identified on the graft to match that of the donor site. A diameterspecific bushing is centered over the planned harvest site and held securely in place (Fig. 5A). The guide must remain locked in position to avoid compromise of the graft harvest. A circular reamer is then placed into the guide and the cylindrical allograft dowel is reamed with cold irrigation to avoid thermal necrosis (Fig. 5B). After the graft is removed, the 12- o clock position is confirmed, and the base of the graft is trimmed to the recipient depth measurements using an ACL saw (Fig. 5C). Prior to implantation, the graft is irrigated with pulsatile lavage to removal any remaining marrow components (Fig. 5D). Immediately prior to graft implantation, the recipient site is dilated using a calibrated dilator to approximately 0.5 mm greater diameter. The 12 o clock positions are aligned, and the graft is press-fit into the recipient site. An oversized tamp is used with very gentle impaction to fully seat the graft (Fig. 4F). Large grafts that may not be fully secured can be anchored using headless bioabsorbable or compression screws as needed. The arthrotomy is then closed using interrupted #1 or #2 suture. The subcutaneous tissue is then closed in the standard fashion. The knee is placed in a hinged brace locked in extension. Outcomes Autograft OAT has been shown to be a successful, durable treatment option for focal chondral defects, yet there are limitations to its utility due to defect size and donor site morbidity. Hangody et al. reported 10-year outcomes after OAT with 92%, 87%, and 79% success rates in the femoral condyle, tibial plateau, and patella, respectively. 6 Pareek et al. performed a systematic review of 10 studies reporting long-term outcomes after OAT with a total of 610 patients at mean Figure 4 Osteochondral D4XX allograft D5XX transplantation of the D6XX femoral D7XX condyle D8XX surgical D9XX technique. (A) The patient is placed on the operating table in the supine position with the right knee prepped and draped in a sterile fashion. A parapatellar arthrotomy is performed to expose the chondral defect of the affected condyle. (B) A cylindrical sizing guide is used to measure the chondral defect and appropriately place a guide pin in the center of the defect. (C) A cannulated bone reamer is placed over the guide pin and the chondral defect is reamed to a depth of appropriately 6-8D10XXmm. (D) The recipient site is then irrigated and prepared by removing any loose fragments. (E) The depth of the recipient site is measured at the 12, 3, 6, and 9 o clock positions to accurately prepare the donor allograft. (F) The allograft plug is press fit into the recipient site to restore the articular surface. 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456

XXOsteochondral Allograft Transplantation and Osteochondral Autograft Transfer 5 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 Figure 5 Osteochondral Allograft Preparation. (A) The intact allograft is placed on the sterile back table. A brushing is placed over the desired allograft donor site and (B) used as a guide to cut an allograft dowel using a circular donor harvester. (C) The desired depth, measured from the recipient site, is marked on the allograft dowel and an ACL saw is used to cut at the appropriate level. (D) The allograft plug is irrigated with antibiotic infuse saline via pulse D1XX lavage to remove any remaining DNA fragments from the allograft prior to implantation. 10.2-year follow-up and found 72% overall survival and a 19% reoperation rate. 7 Overall, patients experienced significant symptomatic improvement by International Knee Documentation CommitteeD27XXand Lysholm scores. 7 Additionally, OAT has been found to have superior outcomes and return to activity rates when compared to microfracture. 8-10 Horas et al. performed a prospective trial reporting increased symptomatic improvement after OAT compared to ACI. 11 However, Lynch et al. performed a systematic review of 9 studies and did not find a significant difference in clinical outcomes when comparing OAT and ACI. 12 Despite the successful long-term outcomes overall, correct patient selection is important as multiple factors have been associated with inferior outcomes. Jakob et al. reported an overall 92% success rate at mean 37-month follow-up, however both lesion size and number of plugs used were associated with inferior outcomes. 13 Specifically, patients treated with mosaicplasty requiring 8-12 plugs more commonly experienced donor site morbidity. 13 Similarly, Pareek et al. reported that increased age, defect size, and prior surgery were correlated with failure. 7 Additionally, Gudas et al. found patients with defects with a size less than 2 cm 2 had significantly higher return to sport rates than those with larger defects further supporting its use primarily for smaller lesions. 14 Allograft OCA in the knee demonstrates successful short-term, midterm, and long-term clinical outcomesd28xx ; however, the results vary depending on the severity of chondral disease, defect location, and patient demographics. 15,16 OCA is most commonly used to treat chondral lesions of the femoral condyles, but can be successfully employed in the patellofemoral joint. 15,17,18 Frank et al. reported a series of 180 patients treated with OCA at 5-year follow-up. 15 While the red29xxoperation rate was high (32%), they found an 87% survival rate with significant symptomatic improvement by Lysholm, International Knee Documentation CommitteeD30XX, Knee Injury and Osteoarthritis Outcome ScoreD31XX, and Short form-12 D32XXphysical component scores. 15 Similarly, a systematic review of OCA long-term outcomes analyzed a total of 251 patients from five studies and found a 75% survival rate at mean 12.3-year follow-up and significant symptomatic improvement measure by Knee Society Function Score, Knee Society Knee Score, and Lysholm score. 16 Although the procedure is largely successful, multiple patient-specific factors have been identified that can impact the outcome of the procedure. Frank et al. found that increased body mass index (BMI), worker s compensation status, and increased number of prior knee procedures were associated with reoperation while only increased BMI and number of prior ipsilateral knee procedures were associated with failure. 15 The effect of BMI on OCA survival is unclear and demonstrates mixed results at short to intermediate term follow-up. 19,20 In other studies, age over 50 years old, symptom duration greater than D3XX1 year have also been identified to be associated with inferior outcomes. 21-23 The location of the chondral defect, extent of chondral disease, and concomitant pathology may also affect the outcome of OCA. The defect size was traditionally thought to negatively affect outcomes, but a recent analysis of OCA size, whether absolute or relative to the femoral condyle width, did not impact the patient reported outcomes at a mean of 6.0 years. 24 Patellofemoral OCA has been associated with less clinical improvement and higher rates of reoperation than femoral condyle lesions. 16 Specifically, Gracitelli et al. found isolated patellar OCA to have a 60.7% reoperation rate and a 28.6% failure rate at mean 9.7-year follow-up. 17 Interestingly, trochlear OCA has been shown to provide excellent clinical improvement and durability with 91.7% 10-year survival. 18 The extent of chondral disease can also affect the outcomes of OCA. Specifically, bipolar or reciprocal chondral defects (femoral condyle and tibial plateau or patella and trochlea) treated with OCA have been found to have significantly higher failure and reoperation rates than unipolar defects and should be utilized only in the correct patient. 25 Rehabilitation Protocol The patient is placed into a hinged knee brace locked in extension immediately postoperatively. The patient is heeltouch weight bearing for the first 6 weeks (Phase I), although early advances in weight bearing may be appropriate for 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572

6 A.V. Stone et al. 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 Q4 some patients. The brace is removed for range of motion only and remains locked in extension for ambulation until D34XX2 weeks postoperatively when it can be discontinued. Phase I physical therapy goals include range of motion, quadriceps strengthening through straight leg raise, and core strengthening. At 6 weeks, patients are advanced to full weight bearing. Phase II (6-8 weeks) therapy goals focus on advancing Phase I exercises. By Phase III (8-12 weeks) physical therapy goals include gait training, closed-chain quadriceps strengthening, and beginning balance training. Phase IV (3-6 months) consists of advancing core strengthening and starting nond35xx impact conditioning. Once the graft is incorporated and adequate body control is established the patient is released to sport (typically 6-8 months depending on graft and healing). Conclusion OAT and OCA both provide patients with excellent clinical outcomes. Proper patient selection, careful evaluation, and graft selections are all critical factors to consider in order to maximize the patient s chances of a successful outcome. References 1. Kang RW, Gomoll AH, Nho SJ, Pylawka TK, Cole BJ: Outcomes of mechanical debridement and radiofrequency ablation in the treatment of chondral defects: a prospective randomized study. J Knee Surg 21:116-121, 2008 2. CotterXXEJ, Frank RM, Wang KC, et al: Clinical outcomes of osteochondral allograft transplantation for secondary treatment of osteochondritis dissecans of the knee in skeletally mature patients. Arthroscopy 2018 3. Cotter EJ, Waterman BR, Kelly MP, et al: Multiple osteochondral allograft transplantation with concomitant tibial tubercle osteotomy for multifocal chondral disease of the knee. Arthrosc Tech 6:e1393-e1398, 2017 4. Frank RM, Lee S, Cotter EJ, et al: Outcomes of osteochondral allograft transplantation with and without concomitant meniscus allograft transplantation: a comparative matched group analysis. Am J Sports Med 46:573-580, 2018 5. Gross AE, Kim W, Las Heras F, et al: Fresh osteochondral allografts for posttraumatic knee defects: long-term followup. Clin Orthop Relat Res 466:1863-1870, 2008 6. Hangody L, F ules P: Autologous osteochondral mosaicplasty for the treatment of full-thickness defects of weight-bearing joints: ten years of experimental and clinical experience. J Bone Joint Surg Am 85-A(Suppl 2):25-32, 2003 7. Pareek A, Reardon PJ, Maak TG, et al: Long-term outcomes after osteochondral autograft transfer: a systematic review at mean follow-up of 10.2 years. Arthroscopy 32:1174-1184, 2016 8. Krych AJ, Harnly HW, Rodeo SA, et al: Activity levels are higher after osteochondral autograft transfer mosaicplasty than after microfracture for articular cartilage defects of the knee: a retrospective comparative study. J Bone Joint Surg Am 94:971-978, 2012 9. Pareek A, Reardon PJ, Macalena JA, et al: Osteochondral autograft transfer versus microfracture in the knee: a meta-analysis of prospective comparative studies at midterm. Arthroscopy 32:2118-2130, 2016 10. Solheim E, Hegna J, Strand T, et al: Randomized study of longterm (15-17 years) outcome after microfracture versus mosaicplasty in knee articular cartilage defects. Am J Sports Med 46:826-831, 2018 11. Horas U, Pelinkovic D, Herr G, et al: Autologous chondrocyte implantation and osteochondral cylinder transplantation in cartilage repair of the knee joint. A prospective, comparative trial. J Bone Joint Surg Am 85- A:185-192, 2003 12. Lynch TS, Patel RM, Benedick A, et al: Systematic review of autogenous osteochondral transplant outcomes. Arthroscopy 31:746-754, 2015 13. Jakob RP, Franz T, Gautier E, et al: Autologous osteochondral grafting in the knee: indication, results, and reflections. Clin Orthop Relat Res: 170-184, 2002 14. Gudas R, Gudaite A, Pocius A, et al: Ten-year follow-up of a prospective, randomized clinical study of mosaic osteochondral autologous transplantation versus microfracture for the treatment of osteochondral defects in the knee joint of athletes. Am J Sports Med 40:2499-2508, 2012 15. Frank RM, Lee S, Levy D, et al: Osteochondral allograft transplantation of the knee: analysis of failures at 5 years. Am J Sports Med 45:864-874, 2017 16. Assenmacher AT, Pareek A, Reardon PJ, et al: Long-term outcomes after osteochondral allograft: a systematic review at long-term follow-up of 12.3 years. Arthroscopy 32:2160-2168, 2016 17. Gracitelli GC, Meric G, Pulido PA, et al: Fresh osteochondral allograft transplantation for isolated patellar cartilage injury. Am J Sports Med 43:879-884, 2015 18. Cameron JI, Pulido PA, McCauley JC, et al: Osteochondral allograft transplantation of the femoral trochlea. Am J Sports Med 44:633-638, 2016 19. Nuelle CW, Nuelle JA, Cook JL, et al: Patient factors, donor age, and graft storage duration affect osteochondral allograft outcomes in knees with or without comorbidities. J Knee Surg 30:179-184, 2017 20. Wang D, Rebolledo BJ, Dare DM, et al: Osteochondral allograft transplantation of the knee in patients with an elevated body mass index. Cartilage 2018. 1947603518754630 21. Gross AE, Shasha N, Aubin P: Long-term followup of the use of fresh osteochondral allografts for posttraumatic knee defects. Clin Orthop Relat Res: 79-87, 2005 22. Levy YD, G ortz S, Pulido PA, et al: Do fresh osteochondral allografts successfully treat femoral condyle lesions. Clin Orthop Relat Res 471:231-237, 2013 23. Krych AJ, Robertson CM, Williams RJ, et al: Return to athletic activity after osteochondral allograft transplantation in the knee. Am J Sports Med 40:1053-1059, 2012 24. Tírico LEP, McCauley JC, Pulido PA, et al: Lesion Size Does Not Predict Outcomes in Fresh Osteochondral Allograft Transplantation. Am J Sports Med 46:900-907, 2018 25. Meric G, Gracitelli GC, G ortz S, et al: Fresh osteochondral allograft transplantation for bipolar reciprocal osteochondral lesions of the knee. Am J Sports Med 43:709-714, 2015 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 621 679 622 680 623 681 624 682 625 683 626 684 627 685 628 686 629 687 630 688