Biologic Impact of Anterior Cruciate Ligament Injury and Reconstruction.

Surgical intervention after anterior cruciate ligament (ACL) tears is typically required because of the limited healing capacity of the ACL. However, mechanical factors and the inflammatory response triggered by the injury and surgery can impact patient outcomes. This review explores key aspects of ACL injury and reconstruction biology, including the inflammatory response, limited spontaneous healing, secondary inflammation after reconstruction, and graft healing processes. Understanding these biologic mechanisms is crucial for developing new treatment strategies and enhancing patient well-being. By shedding light on these aspects, clinicians and researchers can work toward improving quality of life for individuals affected by ACL tears.

Effect of Tibiofemoral Rotation Angle on Graft Failure After Anterior Cruciate Ligament Reconstruction.

BACKGROUND: Coronal and sagittal malalignment of the knee are well-recognized risk factors for failure after anterior cruciate ligament (ACL) reconstruction (ACLR). However, the effect of axial malalignment on graft survival after ACLR is yet to be determined. PURPOSE: To evaluate whether increased tibiofemoral rotational malalignment, namely, tibiofemoral rotation angle (TFA) and tibial tubercle-trochlear groove (TT-TG) distance, is associated with graft failure after ACLR. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: In this retrospective matched control study of a single center's database, 151 patients who underwent revision ACLR because of graft failure (ACLR failure group, defined as symptomatic patients with anterior knee instability and an ACL graft tear appreciated on magnetic resonance imaging [MRI] and confirmed during arthroscopic surgery) were compared with a matched control group of 151 patients who underwent primary ACLR with no evidence of failure after ≥2-year follow-up (intact ACLR group). Patients were matched by sex, age, and meniscal injury during primary ACLR. Axial malalignment was assessed on preoperative MRI through the TFA and the TT-TG distance. Sagittal alignment was measured through the posterior tibial slope on MRI. The optimal TFA cutoff associated with graft failure was identified by a receiver operating characteristic curve. The Kaplan-Meier curve with log-rank analysis was performed to evaluate the influence of the TFA on ACLR longevity. RESULTS: The mean age was 25.7 ± 10.4 years for the ACLR failure group and 25.9 ± 10.0 years for the intact ACLR group. Among all the included patients, 174 (57.6%) were male. In the ACLR failure group, the mean TFA was 5.8°± 4.5° (range, -5° to 16°), while it was 3.0°± 3.3° (range, -3° to 15°) in the intact ACLR group (P < .001). Neither the TT-TG distance nor the posterior tibial slope presented statistical differences between the groups. The receiver operating characteristic curve suggested an optimal TFA cutoff of 4.5° for graft failure (area under the curve = 0.71; P < .001; sensitivity, 68.2%; specificity, 75.5%). Considering this a threshold, patients who had a TFA ≥4.5° had 6.6 times higher odds of graft failure compared with patients with a TFA <4.5° (P < .001). Survival analysis demonstrated a 5-year survival rate of 81% in patients with a TFA <4.5°, while it was 44% in those with a TFA ≥4.5° (P < .001). CONCLUSION: An increased TFA was associated with increased odds of ACLR failure when the TFA was ≥4.5°. Measuring the TFA in patients with ACL tears undergoing reconstruction may inform the surgeon about additional factors that may require consideration before ACLR for a successful outcome.

Systematic Review of Clinical Results After Medial Meniscus Allograft Transplantation Reveals Improved Patient Reported Outcomes at Greater Than 5 Years Follow-Up.

PURPOSE: To systematically summarize the medial meniscus allograft transplantation (MAT) reported outcomes and evaluate whether the surgical technique is associated with allograft extrusion and knee function. METHODS: Systematic review was conducted according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were English-language clinical studies involving arthroscopically assisted medial MAT that reported the surgical technique and the presence of graft extrusion or functional outcomes after surgery. Studies in which outcomes for medial MAT could not be separated from lateral MAT were excluded. Surgical technique, allograft-related characteristics, and clinical outcomes were extracted. RESULTS: Twenty-four studies with 328 medial MAT were included, 58.3% studies qualified as level 4 of evidence, 29.2% as level 3, and 12.5% as level 2. Allograft fixation techniques were bone plug (235/328 [71.6%]), bone bridge/trough (55/328 [16.8%]), and soft-tissue suture fixation only (38/328 [11.6%]). Relative percentage of extrusion after surgery ranged from 24.8% to 53.7%. Major extrusion (>3 mm) ranged from zero to 78%. Overall, functional scores improved after medial MAT. None of surgical techniques were associated with poor functional outcomes or extruded meniscus; however, nonanatomical placement of the anterior and posterior horns appeared to increase meniscus extrusion. CONCLUSION: Medial MAT provides favorable outcomes, with acceptable rates of complication and failure regardless of surgical technique. Although allograft extrusion appears equivalent for both bone plug and soft-tissue fixation techniques, positioning allograft horns at the native meniscal footprint may be critical for preventing extrusion. However, the heterogeneity and low level of evidence of the studies included in this review prevent decisive conclusions regarding optimal MAT fixation techniques, clinical significance of allograft extrusion, or comparative clinical outcomes after medial MAT. LEVEL OF EVIDENCE: Level IV - systematic review of Level II to IV studies.

Association of Sex Mismatch Between Donor and Recipient With Graft Survivorship at 5 Years After Osteochondral Allograft Transplantation.

BACKGROUND: Sex mismatch between donor and recipient has been considered a potential contributor to adverse outcomes after solid organ transplantation. However, the influence of sex mismatching in osteochondral allograft (OCA) transplantation has yet to be determined. PURPOSE: To evaluate whether donor-recipient sex mismatching affects graft survival after OCA transplantation. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: In this review of prospectively collected data, patients who underwent OCA transplantation between November 2013 and November 2017 by a single surgeon were analyzed. Cumulative survival was assessed via the Kaplan-Meier method using log-rank tests to compare patients with similar donor groups. Multivariable Cox regression analysis adjusted for patient age, graft size, and body mass index was used to evaluate the influence of donor-recipient sex on graft survival. RESULTS: A total of 154 patients were included: 102 (66.2%) who received OCAs from a same-sex donor and 52 (33.8%) who received OCAs from a different-sex donor. At 5-year follow-up, a significantly lower graft survival rate was observed for different-sex donor transplantation in comparison with same-sex donorship (63% vs 92%; P = .01). When correcting for age, graft size, and body mass index, donor-recipient sex-mismatch transplantation demonstrated a 2.9-times greater likelihood to fail at 5 years compared with donor-recipient same-sex transplantation (95% CI, 1.11-7.44; P = .03). A subgroup analysis showed no significant difference in graft survival between the female-to-female and female-to-male groups (91% and 84%, respectively). Conversely, male-to-male transplantation demonstrated a significantly higher cumulative 5-year survival (94%; P = .04), whereas lower survival was found with male-to-female donorship (64%; P = .04). Multivariable Cox regression indicated a 2.6-times higher likelihood of failure for the male-to-female group in comparison with the other groups (95% CI, 1.03-6.69; P = .04). Male-to-male transplantation had a tendency toward decreased likelihood of OCA failure (hazard ratio, 0.33), although without statistical significance (95% CI, 0.11-1.01; P = .052). CONCLUSION: Mismatch between donor and recipient sex had a negative effect on OCA survival after transplantation, particularly in those cases when male donor tissue was transplanted into a female recipient.

Metrics of OsteoChondral Allografts (MOCA) Group Consensus Statements on the Use of Viable Osteochondral Allograft.

BACKGROUND: Osteochondral allograft (OCA) transplantation has evolved into a first-line treatment for large chondral and osteochondral defects, aided by advancements in storage protocols and a growing body of clinical evidence supporting successful clinical outcomes and long-term survivorship. Despite the body of literature supporting OCAs, there still remains controversy and debate in the surgical application of OCA, especially where high-level evidence is lacking. PURPOSE: To develop consensus among an expert group with extensive clinical and scientific experience in OCA, addressing controversies in the treatment of chondral and osteochondral defects with OCA transplantation. STUDY DESIGN: Consensus statement. METHODS: A focus group of clinical experts on OCA cartilage restoration participated in a 3-round modified Delphi process to generate a list of statements and establish consensus. Questions and statements were initially developed on specific topics that lack scientific evidence and lead to debate and controversy in the clinical community. In-person discussion occurred where statements were not agreed on after 2 rounds of voting. After final voting, the percentage of agreement and level of consensus were characterized. A systematic literature review was performed, and the level of evidence and grade were established for each statement. RESULTS: Seventeen statements spanning surgical technique, graft matching, indications, and rehabilitation reached consensus after the final round of voting. Of the 17 statements that reached consensus, 11 received unanimous (100%) agreement, and 6 received strong (80%-99%) agreement. CONCLUSION: The outcomes of this study led to the establishment of consensus statements that provide guidance on surgical and perioperative management of OCAs. The findings also provided insights on topics requiring more research or high-quality studies to further establish consensus and provide stronger evidence.

An Expert Consensus Statement on the Management of Large Chondral and Osteochondral Defects in the Patellofemoral Joint.

BACKGROUND: Cartilage lesions of the patellofemoral joint constitute a frequent abnormality. Patellofemoral conditions are challenging to treat because of complex biomechanics and morphology. PURPOSE: To develop a consensus statement on the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint using a modified Delphi technique. STUDY DESIGN: Consensus statement. METHODS: A working group of 4 persons generated a list of statements related to the functional anatomy, indications, donor graft considerations, surgical treatment, and rehabilitation for the management of large chondral and osteochondral defects in the patellofemoral joint to form the basis of an initial survey for rating by a group of experts. The Metrics of Osteochondral Allografts (MOCA) expert group (composed of 28 high-volume cartilage experts) was surveyed on 3 occasions to establish a consensus on the statements. In addition to assessing agreement for each included statement, experts were invited to propose additional statements for inclusion or to suggest modifications of existing statements with each round. Predefined criteria were used to refine statement lists after each survey round. Statements reaching a consensus in round 3 were included within the final consensus document. RESULTS: A total of 28 experts (100% response rate) completed 3 rounds of surveys. After 3 rounds, 36 statements achieved a consensus, with over 75% agreement and less than 20% disagreement. A consensus was reached in 100.00% of the statements relating to functional anatomy of the patellofemoral joint, 88.24% relating to surgical indications, 100.00% relating to surgical technical aspects, and 100.00% relating to rehabilitation, with an overall consensus of 95.5%. CONCLUSION: This study established a strong expert consensus document relating to the functional anatomy, surgical indications, donor graft considerations for osteochondral allografts, surgical technical aspects, and rehabilitation concepts for the management of large chondral and osteochondral defects in the patellofemoral joint. Further research is required to clinically validate the established consensus statements and better understand the precise indications for surgery as well as which techniques and graft processing/preparation methods should be used based on patient- and lesion-specific factors.

Medial Tibial Slope Determined by Plain Radiography Is Not Associated with Primary or Recurrent Anterior Cruciate Ligament Tears.

Increased tibial slope may be associated with anterior cruciate ligament (ACL) injuries, although potential confounding effects from various patient characteristics and radiographic quantification methods have not been rigorously studied. The association of the slope of the lateral plateau with recurrent ACL injury after primary ACL reconstruction has recently been reported, but the role of medial slope is less well defined. The purpose of this study was to (1) assess medial tibial slope measurement reliability among examiners, (2) compare medial tibial slope values between patients undergoing primary ACL reconstruction, reinjured patients undergoing revision ACL reconstruction, and a control cohort with an intact ACL, (3) analyze if the medial tibial slope is an independent risk factor for noncontact ACL injury, and (4) assess how different anatomical references affect medial tibial slope values. A total of 206 patients were enrolled into one of three groups: (1) ACL-intact controls (CONTROL, n = 83), (2) first-time ACL-injured patients (PRIMARY, n = 77), and (3) patients undergoing revision ACL reconstruction (REVISION, n = 46). Three fellowship-trained sports medicine surgeons performed repeated measurements of plain lateral radiographs. The medial tibial slope was determined by three anatomical references: anterior tibial cortex (anterior tibial slope [ATS]), posterior tibial cortex (posterior tibial slope [PTS]), and the anatomical long axis of the tibia (composite tibial slope [CTS]). Substantial intra- and interobserver reliabilities were established by the intraclass correlation coefficient of 0.73 to 0.89. There was no difference in CTS, ATS, or PTS comparing the CONTROL, PRIMARY, and REVISION groups upon univariate analyses. Multivariable logistic regression model showed that none of the slope values was independently associated with ACL injury. The mean ATS for all 206 subjects was 4 and 8 degrees greater than the mean CTS and PTS, respectively. ATS correlated only moderately to PTS. We concluded that medial tibial slope measured on radiographs is not associated with primary or recurrent ACL injury, and has substantial variation and suboptimal correlation when using different anatomical references despite good inter- and intraobserver reliabilities.

Revision and Salvage Management: Proceedings of the International Consensus Meeting on Cartilage Repair of the Ankle.

BACKGROUND: The evidence supporting best practice guidelines in the field of cartilage repair of the ankle are based on both low quality and low levels of evidence. Therefore, an international consensus group of experts was convened to collaboratively advance toward consensus opinions based on the best available evidence on key topics within cartilage repair of the ankle. The purpose of this article was to report on the consensus statements on "Revision and Salvage Management" developed at the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. METHODS: Seventy-five international experts in cartilage repair of the ankle representing 25 countries and 1 territory were convened and participated in a process based on the Delphi method of achieving consensus. Questions and statements were drafted within 11 working groups focusing on specific topics within cartilage repair of the ankle, after which a comprehensive literature review was performed and the available evidence for each statement was graded. Discussion and debate occurred in cases where statements were not agreed on in unanimous fashion within the working groups. A final vote was then held, and the strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; unanimous, 100%. RESULTS: A total of 8 statements on revision and salvage management reached consensus during the 2017 International Consensus Meeting on Cartilage Repair of the Ankle. One achieved unanimous support and 7 reached strong consensus (greater than 75% agreement). All statements reached at least 85% agreement. CONCLUSIONS: This international consensus derived from leaders in the field will assist clinicians with revision and salvage management in the cartilage repair of the ankle.

Graft Considerations in Posterior Cruciate Ligament Reconstruction.

PURPOSE OF REVIEW: To highlight current and established concepts regarding PCL injury and reconstruction. RECENT FINDINGS: Recent biomechanical and clinical studies have brought attention to improved surgical techniques and clinical outcomes of PCL reconstruction. In contrast to anterior cruciate ligament (ACL) injuries, isolated posterior cruciate ligament (PCL) injuries occur much less frequently and have traditionally been treated non-operatively. Even when a PCL injury meets operative indications, outcomes of PCL reconstruction historically do not match the success rates of ACL reconstruction procedures. As such, there remains controversy regarding appropriate indications and techniques for surgical repair leading to a paucity of conclusive data regarding surgical outcomes. Recently, however, there has been an increase in focus on the role of the PCL in proper knee biomechanics and negative long-term sequelae of chronic PCL insufficiency. This improved understanding has led to advancements in surgical technique and graft options for PCL reconstruction.

The University of the National Football League: How Technology, Injury Surveillance, and Health Care Have Improved the Safety of America's Game.

American football has become one of the most popular sports in the United States. Despite the millions of players at all levels of competition who gain the physical, social, and psychological rewards that football provides, many interested stakeholders continue to ask, "Is football safe?" Although there are only approximately 1,700 players on National Football League (NFL) rosters, the injuries they sustain have garnered the most attention-and criticism-from the national media. Increased public awareness of the injury potential football possesses has led to an open debate and a major shift in public sentiment over the past 5 years. Although no sport is perfectly safe, the question is whether it can be made relatively safe and if the long-term consequences are worth the risk. This article reviews the methods by which one sports league-the NFL-has used advances in medical technology and injury surveillance to improve the health and safety of its players.

Osteochondral allograft transplantation in cartilage repair: Graft storage paradigm, translational models, and clinical applications.

The treatment of articular cartilage injury and disease has become an increasingly relevant part of orthopaedic care. Articular cartilage transplantation, in the form of osteochondral allografting, is one of the most established techniques for restoration of articular cartilage. Our research efforts over the last two decades have supported the transformation of this procedure from experimental "niche" status to a cornerstone of orthopaedic practice. In this Kappa Delta paper, we describe our translational and clinical science contributions to this transformation: (1) to enhance the ability of tissue banks to process and deliver viable tissue to surgeons and patients, (2) to improve the biological understanding of in vivo cartilage and bone remodeling following osteochondral allograft (OCA) transplantation in an animal model system, (3) to define effective surgical techniques and pitfalls, and (4) to identify and clarify clinical indications and outcomes. The combination of coordinated basic and clinical studies is part of our continuing comprehensive academic OCA transplant program. Taken together, the results have led to the current standards for OCA processing and storage prior to implantation and also novel observations and mechanisms of the biological and clinical behavior of OCA transplants in vivo. Thus, OCA transplantation is now a successful and increasingly available treatment for patients with disabling osteoarticular cartilage pathology.

Combined osteochondral allograft and meniscal allograft transplantation: a survivorship analysis.

INTRODUCTION: The efficacy of meniscal allograft transplantation (MAT) and osteochondral allografting (OCA) as individual treatment modalities for select applications is well established. MAT and OCA are considered symbiotic procedures due to a complementary spectrum of indications and reciprocal contraindications. However, few outcomes of concomitant MAT and OCA have been reported. This study is a retrospective review of patients who received simultaneous MAT and OCA between 1983 and 2011. METHODS: Forty-eight (twenty-nine male: nineteen female) patients with a median age of 35.8 years (15-66) received combined MAT and OCA procedures between 1983 and 2011. Forty-three patients had received previous surgery with a median of 3 procedures (1-11 procedures). The underlying diagnosis was trauma (tibial plateau fracture) in 33 % with osteoarthritis predominating in 54.2 % of cases. Thirty-one patients received a lateral meniscus, 16 received a medial meniscus and one patient received bilateral MAT. The median number of OCAs was two per patient (1-5 grafts), with a median graft area of 15 cm(2) (0.7-41 cm(2)). There were 21 unipolar, 24 bipolar (tibiofemoral) and three multifocal lesions. Thirty-six MATs constituted a compound tibial plateau OCA with native meniscus attached. At follow-up, failure was defined as any procedure resulting in removal or revision of one or more of the grafts. Patients completed the modified Merle d'Aubigné and Postel (18-point) scale, Knee Society Function (KS-F) score, and subjective International Knee Documentation Committee (IKDC) scores. Patient satisfaction was also captured. RESULTS: Twenty-six of 48 patients (54.2 %) required reoperation, but only 11 patients (22.9 %) were noted to have failed (10 MAT and 11 OCA). The mean time to failure was 3.2 years (95 % CI 1.5-4.9 years) and 2.7 years (95 % CI 1.3-4.2 years) for MAT and OCA, respectively. The 5-year survivorship was 78 and 73 % for MAT and OCA respectively, and 69 and 68 % at 10 years. Six of the failures were in the OA cases and one was an OCD lesion where bipolar grafts were utilized. The OCD case underwent a revision OCA and remains intact. The others were converted to knee arthroplasty. One case failed due to early deep infection, ultimately requiring arthrodesis. Of those with grafts still intact, the mean clinical follow-up was 6.8 years (1.7-17.1 years). Statistically significant improvements in all outcome scores were noted between baseline and the latest follow-up. In total, 90 % of those responding would have the surgery again and 78 % were either extremely satisfied or satisfied with the outcome. CONCLUSION: The overall success rate of concomitant MAT and OCA was comparable with reported results for either procedure in isolation. A trend towards  a worse outcome was observed with bipolar tibiofemoral grafts in the setting of OA. Comparatively better results in less advanced, unipolar disease could suggest a benefit to early intervention that might merit a lower treatment threshold for combined MAT and OCA. LEVEL OF EVIDENCE: IV.

Fresh osteochondral allograft transplantation for bipolar reciprocal osteochondral lesions of the knee.

BACKGROUND: Osteochondral allograft (OCA) transplantation is an effective treatment option for chondral and osteochondral defects of the knee. HYPOTHESIS: Patients treated with OCAs for reciprocal bipolar lesions of the knee would demonstrate significant clinical improvement. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Between 1983 and 2010, OCAs were implanted for bipolar chondral lesions in 46 patients (48 knees). The 21 male and 25 female patients averaged 40 years of age (range, 15-66 years). Thirty-four lesions were tibiofemoral, and 14 were patellofemoral. Forty-two knees (88%) had undergone a mean of 3.4 previous surgeries (range, 1-8). The mean allograft area was 19.2 cm(2). Clinical evaluation included the modified Merle d'Aubigné-Postel (18-point), International Knee Documentation Committee (IKDC) pain and function, and Knee Society function (KS-F) scores. Further surgeries on the operative joint were documented. RESULTS: Survivorship of the bipolar OCA was 64.1% at 5 years. Thirty knees underwent further surgery; 22 knees (46%) were considered failures (3 OCA revisions, 14 total knee arthroplasties, 2 unicondylar arthroplasties, 2 arthrodeses, and 1 patellectomy). Among patients whose OCA was still in situ at follow-up, the mean follow-up was 7 years (range, 2.0-19.7 years). The mean 18-point score improved from 12.1 to 16.1; 88% (23/26 knees) of surviving allografts scored ≥15. The mean IKDC pain score improved from 7.5 to 4.7, and the mean IKDC function score improved from 3.4 to 7.0. The mean KS-F score improved from 70.5 to 84.1. CONCLUSION: Osteochondral allograft transplantation is a useful salvage treatment option for reciprocal bipolar cartilage lesions of the knee. High reoperation and failure rates were observed, but patients with surviving allografts showed significant clinical improvement.

Fresh osteochondral allograft transplantation for isolated patellar cartilage injury.

BACKGROUND: The treatment of patellofemoral cartilage injuries can be challenging. Osteochondral allograft (OCA) transplantation has been used as a treatment option for a range of cartilage disorders. PURPOSE: To evaluate functional outcomes and survivorship of the grafts among patients who underwent OCA for patellar cartilage injuries. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: An institutional review board-approved OCA database was used to identify 27 patients (28 knees) who underwent isolated OCA transplantation of the patella between 1983 and 2010. All patients had a minimum 2-year follow-up. The mean age of the patients was 33.7 years (range, 14-64 years); 54% were female. Twenty-six (92.9%) knees had previous surgery (mean, 3.2 procedures; range, 1-10 procedures). The mean allograft area was 10.1 cm(2) (range, 4.0-18.0 cm(2)). Patients returned for clinical evaluation or were contacted via telephone for follow-up. The number and type of reoperations were assessed. Any reoperation resulting in removal of the allograft was considered a failure of the OCA transplantation. Patients were evaluated pre- and postoperatively using the modified Merle d'Aubigné-Postel (18-point) scale, the International Knee Documentation Committee (IKDC) pain, function, and total scores, and the Knee Society function (KS-F) score. Patient satisfaction was assessed at latest follow-up. RESULTS: Seventeen of the 28 knees (60.7%) had further surgery after the OCA transplantation; 8 of the 28 knees (28.6%) were considered OCA failures (4 conversions to total knee arthroplasty, 2 conversions to patellofemoral knee arthroplasty, 1 revision OCA, 1 patellectomy). Patellar allografting survivorship was 78.1% at 5 and 10 years and 55.8% at 15 years. Among the 20 knees (71.4%) with grafts in situ, the mean follow-up duration was 9.7 years (range, 1.8-30.1 years). Pain and function improved from the preoperative visit to latest follow-up, and 89% of patients were extremely satisfied or satisfied with the results of the OCA transplantation. CONCLUSION: OCA transplantation was successful as a salvage treatment procedure for cartilage injuries of the patella.

A case of delayed presentation of thigh compartment syndrome.

BACKGROUND: Thigh compartment syndrome is a rare and devastating process. It generally occurs within hours to days of a traumatic event, although cases have been reported nearly 2 weeks after the initial event. OBJECTIVES: To evaluate the literature describing the timing between inciting event and presentation of thigh compartment syndromes, with a focus on delayed presentations of this rare condition. To describe the unique properties of thigh compartments, and finally, to review the anatomy and techniques needed to measure the compartment pressures of the thigh. CASE REPORT: A case of a 54-year-old man is presented. He sustained trauma to his thigh 17 days prior to presenting to our ED with severe, sudden-onset pain in his right thigh. Compartment pressures were measured and confirmed the diagnosis of compartment syndrome caused by two large intramuscular hematomas. No other contributing events were identified. CONCLUSIONS: Compartment syndrome in the thigh should be considered in patients with a concerning examination and a history of recent trauma. This particular case represents the longest reported time between injury and development of a thigh compartment syndrome.

The role of immunologic response in fresh osteochondral allografting of the knee.

BACKGROUND: Osteochondral allografting, a restorative treatment option for articular cartilage lesions in the knee, involves transplantation of fresh osteochondral tissue with no tissue matching. Although retrieval studies have not consistently shown evidence of immunologic response, development of anti-human leukocyte antigen class I cytotoxic antibodies has been observed in allograft recipients. HYPOTHESIS: Postallograft antibody formation is related to graft size and may affect clinical outcome. STUDY DESIGN: Case-control study; Level of evidence, 3. METHODS: This study retrospectively compared 42 antibody-positive postallograft patients with 42 antibody-negative patients. Groups were matched for age, sex, and body mass index but not intra-articular disease severity. Seventeen patients (20%) were lost to follow-up. Of the remaining 67 patients (33 antibody-positive and 34 antibody-negative), average follow-up time was 50.3 months (range, 24-165 months). Mean age was 38.1 years (range, 15-68 years) with 58% being male. Graft area was categorized as small (<5 cm2), medium (5-10 cm2), or large (>10 cm2). Graft survival and Knee Society function scores were used to measure clinical outcome. RESULTS: Of the 84 patients, 80 had graft area data. Of 27 patients with large graft area, 19 (70%) had positive postoperative antibody screens, compared with 1 of 16 (6%) with small graft area (P < .001). Graft survival rates in the antibody-positive and antibody-negative groups were 64% and 79%, respectively (P = .152). Mean postoperative Knee Society function scores in surviving antibody-positive and antibody-negative groups were 88.3 and 84.6 points, respectively (P = .482). CONCLUSION: Antibody development after fresh, non-tissue-matched osteochondral allograft transplants in the knee appears related to graft size. No difference was observed in clinical outcome between groups. Graft survival is multifactorial, and the effect that the immunologic response has on clinical outcome merits further investigation.

Bipolar fresh osteochondral allografting of the tibiotalar joint.

BACKGROUND: Tibiotalar arthritis in the young, active patient is a debilitating condition with limited treatment options. Bipolar tibiotalar fresh osteochondral allograft transplantation was conceived as a possible alternative to arthrodesis and arthroplasty. We reported our experience with bipolar ankle osteochondral allografts for the treatment of tibiotalar joint arthritis. METHODS: Between 1999 and 2008, we performed bipolar ankle allografts in eighty-eight ankles (eighty-four patients). Eighty-six ankles (eighty-two patients) had a minimum follow-up duration of two years. The mean patient age was forty-four years and 52% of the patients were male. Evaluation included frequency and type of reoperations, the Olerud-Molander Ankle Score, pain, function, and patient satisfaction. Radiographs were evaluated for graft healing, joint space narrowing, and graft collapse. RESULTS: The mean duration of follow-up was 5.3 years (range, two to eleven years). Thirty-six (42%) of the eighty-six ankles that had undergone allograft had further surgery since implantation. Of the eighty-six ankles, twenty-five ankles (29%) had undergone graft-related reoperations and were considered clinical failures (ten underwent revision allografts, seven underwent arthrodeses, six underwent conversions to total ankle arthroplasty, and two underwent below-the-knee amputations) and eleven ankles (13%) had had reoperations that were not necessarily related to the graft (e.g., implant removal, debridement, synovectomy, or distraction). Survivorship of the osteochondral allograft was 76% at five years and 44% at ten years. The mean Olerud-Molander Ankle Score was 61 points at the time of the latest follow-up. The majority of patients reported satisfaction (92%) with osteochondral allograft transplantation and less pain (85%) and improved function (83%) after the procedure. CONCLUSIONS: Transplantation of a fresh bipolar ankle osteochondral allograft for the treatment of tibiotalar arthritis resulted in acceptable outcomes in this difficult population, with most patients having improved objective and subjective outcome measures. Subjective satisfaction was high in spite of the 29% clinical failure rate. Osteochondral allograft failure did not limit further surgical options. We concluded that transplantation of a bipolar ankle allograft is a useful alternative in carefully selected patients with advanced tibiotalar arthritis.

Do fresh osteochondral allografts successfully treat femoral condyle lesions?

BACKGROUND: Fresh osteochondral allograft transplantation is an increasingly common treatment option for chondral and osteochondral lesions in the knee, but the long-term outcome is unknown. QUESTIONS/PURPOSES: We determined (1) pain and function, (2) frequency and types of reoperations, (3) survivorship at a median of 13.5 years, and (4) predictors of osteochondral allograft failure in the distal femur. METHODS: We evaluated 122 patients (129 knees) who underwent osteochondral allograft transplantation of the femoral condyle. Mean age was 33 years and 53% were male. Clinical evaluation included the modified Merle d'Aubigné-Postel (18-point), IKDC, and Knee Society function (KS-F) scores. We defined graft failure as revision osteochondral allografting or conversion to arthroplasty. We determined whether patient characteristics or attributes of the graft influenced failure. Minimum followup was 2.4 years (median, 13.5 years); 91% had more than 10 years of followup. RESULTS: Mean modified Merle d'Aubigné-Postel score improved from 12.1 to 16, mean IKDC pain score from 7.0 to 3.8, mean IKDC function score from 3.4 to 7.2, and mean KS-F score from 65.6 to 82.5. Sixty-one knees (47%) underwent reoperations. Thirty-one knees (24%) failed at a mean of 7.2 years. Survivorship was 82% at 10 years, 74% at 15 years, and 66% at 20 years. Age of more than 30 years at time of surgery and having two or more previous surgeries for the operated knee were associated with allograft failure. CONCLUSIONS: Followup of femoral condyle osteochondral allografting demonstrated durable improvement in pain and function, with graft survivorship of 82% at 10 years.

Treatment of articular cartilage defects in the goat with frozen versus fresh osteochondral allografts: effects on cartilage stiffness, zonal composition, and structure at six months.

BACKGROUND: Understanding the effectiveness of frozen as compared with fresh osteochondral allografts at six months after surgery and the resultant consequences of traditional freezing may facilitate in vivo maintenance of cartilage integrity. Our hypothesis was that the state of the allograft at implantation affects its performance after six months in vivo. METHODS: The effect of frozen as compared with fresh storage on in vivo allograft performance was determined for osteochondral allografts that were transplanted into seven recipient goats and analyzed at six months. Allograft performance was assessed by examining osteochondral structure (cartilage thickness, fill, surface location, surface degeneration, and bone-cartilage interface location), zonal cartilage composition (cellularity, matrix content), and cartilage biomechanical function (stiffness). Relationships between cartilage stiffness or cartilage composition and surface degeneration were assessed with use of linear regression. RESULTS: Fresh allografts maintained cartilage load-bearing function, while also maintaining zonal organization of cartilage cellularity and matrix content, compared with frozen allografts. Overall, allograft performance was similar between fresh allografts and nonoperative controls. However, cartilage stiffness was approximately 80% lower (95% confidence interval [CI], 73% to 87%) in the frozen allografts than in the nonoperative controls or fresh allografts. Concomitantly, in frozen allografts, matrix content and cellularity were approximately 55% (95% CI, 22% to 92%) and approximately 96% (95% CI, 94% to 99%) lower, respectively, than those in the nonoperative controls and fresh allografts. Cartilage stiffness correlated positively with cartilage cellularity and matrix content, and negatively with surface degeneration. CONCLUSIONS: Maintenance of cartilage load-bearing function in allografts is associated with zonal maintenance of cartilage cellularity and matrix content. In this animal model, frozen allografts displayed signs of failure at six months, with cartilage softening, loss of cells and matrix, and/or graft subsidence, supporting the importance of maintaining cell viability during allograft storage and suggesting that outcomes at six months may be indicative of long-term (dys)function. CLINICAL RELEVANCE: Fresh versus frozen allografts represent the "best versus worst" conditions with respect to chondrocyte viability, but "difficult versus simple" with respect to acquisition and distribution. The outcomes described from these two conditions expand the current understanding of in vivo cartilage remodeling and describe structural properties (initial graft subsidence), which may have implications for impending graft failure.