Autograft Demonstrates Superior Outcomes for Revision Anterior Cruciate Ligament Reconstruction When Compared With Allograft: A Systematic Review.

BACKGROUND: Multiple studies have compared outcomes among patients undergoing revision anterior cruciate ligament reconstruction (ACLR) with autograft versus allograft, but these data are inconsistently reported and long-term outcomes depending on graft type are yet to be determined. PURPOSE: To perform a systematic review of clinical outcomes after revision ACLR (rACLR) with autograft versus allograft. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic review of the literature was performed by searching PubMed, the Cochrane Library, and Embase to identify studies that compared the outcomes of patients undergoing rACLR with autograft versus allograft. The search phrase used was autograft allograft revision anterior cruciate ligament reconstruction. Graft rerupture rates, return-to-sports rates, anteroposterior laxity, and patient-reported outcome scores (subjective International Knee Documentation Committee, Tegner, Lysholm, and Knee injury and Osteoarthritis Outcome Score) were evaluated. RESULTS: Eleven studies met inclusion criteria, including 3011 patients undergoing rACLR with autograft (mean age, 28.9 years) and 1238 patients undergoing rACLR with allograft (mean age, 28.0 years). Mean follow-up was 57.3 months. The most common autograft and allograft types were bone-patellar tendon-bone grafts. Overall, 6.2% of patients undergoing rACLR experienced graft retear, including 4.7% in the autograft group and 10.2% in the allograft group (P < .0001). Among studies that reported return-to-sports rates, 66.2% of patients with an autograft returned to sports as opposed to 45.3% of patients with an allograft (P = .01). Two studies found significantly greater postoperative knee laxity in the allograft group as compared with the autograft group (P < .05). Among all patient-reported outcomes, 1 study found 1 significant difference between groups: patients with an autograft had a significantly higher postoperative Lysholm score when compared with patients with an allograft. CONCLUSION: Patients undergoing revision ACLR with an autograft can be expected to experience lower rates of graft retear, higher rates of return to sports, and less postoperative anteroposterior knee laxity when compared with patients undergoing revision ACLR with an allograft.

Surgical Stabilization for Recurrent Patellar Instability in Competitive Wrestlers: Outcomes, Reoperations, and Return to Play at 6-Year Mean Follow-up.

BACKGROUND: The extent to which recurrent patellar instability (RPI) affects wrestlers has not been thoroughly examined. PURPOSE: To assess return to wrestling (RTW), patient-reported outcomes, and reoperation rates after patellofemoral stabilization surgery (PFSS) for RPI in a cohort of competitive wrestlers. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All competitive wrestlers with a history of RPI and subsequent PFSS performed at a single institution between 2000 and 2020 were identified. Primary PFSS procedures included medial patellofemoral (MPFL) reconstruction (n = 31; 50%); MPFL repair (n = 22; 35.5%); or other PFSS (n = 9; 14.5%), such as tibial tubercle osteotomy, lateral retinacular release, and/or medial retinacular reefing. Exclusion criteria included revision PFSS or concomitant anterior cruciate ligament reconstruction or multiligament knee injury. Surgical failure was defined as subsequent patellar dislocation despite operative management or need for secondary PFSS. RESULTS: Ultimately, 62 knees in 56 wrestlers with a mean age of 17.0 years (range, 14.0-22.8 years) were included at a mean follow-up of 6.6 years (range, 2.0-18.8 years). RTW occurred in 55.3% of wrestlers at a mean ± SD 8.8 ± 6.7 months. Among PFSS types, no differences were observed in rates of RTW (P = .676), postoperative pain (P = .176), Tegner activity level (P = .801), International Knee Documentation Committee (P = .378), Lysholm (P = .402), or Kujala scores (P = .370). RPI was the most common postoperative complication (n = 13; 21.0%). MPFL reconstruction had the lowest rate of RPI (6.5% vs 27.3% [repair] vs 55.6% [other]; P = .005) and surgical failure (9.7% vs 31.8% [repair] vs 55.6% [other]; P = .008). Kaplan-Meier survivorship free from surgical failure of the entire cohort was 91.9% at 1 year, 77.7% at 5 years, and 65.7% at 15 years. MPFL reconstruction had the highest survivorship when compared with MPFL repair and other PFSS up to 10 years after the index surgery (90.3% vs 64.1% vs 27.8%; P = .048). CONCLUSION: RPI remains a concern for competitive wrestlers after PFSS. MPFL reconstruction may serve as a more durable surgical treatment option with lower rates of RPI and failure when compared with other PFSS procedures at up to 10 years after surgery.

Pubic Symphysis to Sacrococcygeal Joint: A Poor Correlate to Other Spinopelvic Measurements.

BACKGROUND: The hip-spine relationship is increasingly recognized as critical for optimizing stability following total hip arthroplasty (THA). However, these measurements are not routinely obtained during THA workup. It has been suggested that insight can be gained from supine antero-posterior pelvis radiograph, measuring the distance from the superior border of the pubic symphysis to the sacro-coccygeal joint (PSCD). This study assessed the correlation between PSCD and lateral lumbar radiographic metrics in a cohort of preoperative THA patients. METHODS: We retrospectively evaluated 250 consecutive patients who underwent THA with preoperative supine antero-posterior pelvis and lateral lumbar radiographs. The mean age was 68 years (range, 42 to 89), 61% were women, and the mean body mass index was 30 kg/m2 (range, 19 to 52). Two reviewers measured PSCD, pelvic tilt (PT), sacral slope (SS), pelvic incidence (PI), and lumbar lordosis (LL). Inter-observer reliability was calculated for all measurements, and correlation coefficients were calculated for PSCD with respect to PT, SS, PI, and LL. RESULTS: Correlations between PSCD and lumbar radiographic metrics were all statistically significant, except for PI in men but graded as "weak" or "very weak" for men and women, respectively, as follows: PT = -0.30 (P < .01) and -0.46 (P < .01); SS = 0.27 (P < .01) and 0.22 (P < .01); PI = -0.04 (P = .70) and -0.19 (P = .02); and LL = 0.45 (P < .01) and 0.30 (P < .01). Inter-observer reliability was graded as "strong" for every metric. CONCLUSION: The PSCD was weakly correlated with all evaluated lateral lumbar radiographic metrics in both sexes, despite strong inter-observer reliability. Therefore, PSCD cannot reliably serve as a proxy for evaluating the hip-spine relationship.

Lack of radiosensitivity predicts poor disease specific survival in myxoid liposarcoma.

BACKGROUND: Compared to other sarcomas, myxoid liposarcoma (ML) is known to be radiosensitive, with improved oncologic outcomes. Although these tumors "shrink" following radiotherapy, there is a paucity of data examining the degree of radiosensitivity and oncologic outcome. The purpose of the study was to evaluate pre- and postradiotherapy tumor volume to determine if size reduction impacts outcome. METHODS: We reviewed 62 patients with ML undergoing surgical resection combined with preoperative radiotherapy, with pre- and postradiotherapy MRI. This included 34 (55%) males, with a mean age of 47 ± 14 years. All tumors were deep to the fascia, and 12 (19%) patients had tumors with a >5% round-cell component. RESULTS: The mean volume reduction was 54% ± 29%. Compared to patients with >25% volume reduction, patients with reduction ≤25% had worse 10-year disease specific survival (86% vs. 37%, p < 0.01), in addition to an increased risk of metastatic disease (HR 4.63, p < 0.01) and death due to disease (HR 4.52, p < 0.01). CONCLUSION: Lack of volume reduction is a risk factor for metastatic disease and subsequent death due to disease in patients with extremity ML treated with combined preoperative radiotherapy and surgery. This data could be used to stratify patients for adjuvant therapies and follow-up intervals.

The Effect of Amniotic Tissue on Spinal Interventions: A Systematic Review.

BACKGROUND: Amniotic membrane tissue has been thought to potentiate healing in many soft tissue conditions. Specifically, recent studies have shown its therapeutic potential for treatment in the setting of spinal pathologies. The purpose of this study is to thoroughly review the existing scientific literature and evidence concerning the clinical use of amniotic membrane-derived biologic agents on postoperative outcomes following spinal surgery. METHODS: A systematic review was conducted following preferred reporting items for systematic reviews and meta-analyses guidelines using PubMed, Embase, and Cochrane databases up to December 2020 to identify animal and clinical studies examining the therapeutic potential for amniotic membrane tissue in the setting of spinal pathologies (including disc herniation, prevention of epidural fibrosis, and spinal fusion). Studies were broken down into 2 categories: experimental model type and the type of amnion product being analyzed. RESULTS: A total of 12 studies (4 clinical studies and 8 studies utilizing animal models) met inclusion criteria. Additionally, the major types of amnion product were divided into cryopreserved/freeze-dried amniotic membrane, human amniotic fluid, human amniotic membrane, cross-linked amniotic membrane, and amnion-derived epithelial cells. While heterogeneity of study design precludes definitive specific results reporting, most studies showed positive benefits on healing/outcomes with amniotic augmentation. Specifically, amnion products have shown promising effects in reducing epidural adhesions and scar tissue after spine surgery, improving spinal fusion rate and postoperative pain scores, and promoting better functional outcomes after spine surgery. CONCLUSIONS: A review of the limited number of reported studies revealed a wide variety of amniotic membrane preparations, treatment regimens, and indications, which limit definitive conclusions. To date, while there is no definitive clinical proof that amniotic tissues enhance tissue repair or regeneration, the aggregate results demonstrate promising basic science and outcomes potential in spinal surgery. Further study is warranted to determine whether this application is appropriate in the clinical setting. CLINICAL RELEVANCE: This systematic review provides a summary of the existing literature regarding the use of amniotic membrane preparations, treatment regimens, and indications within spinal surgery. With the growing popularity and utilization of biologic agents such as amniotic membrane-derived products in orthopedic and neurologic surgery, this systematic review gives physicians a concise summary on the outcomes and indications associated with amniotic membrane products.

Painful Fibrous Nonunion of a Posterior Oblique Ligament Bony Avulsion Fracture Associated With Anterior Cruciate Ligament Tear: A Case Report.

CASE: This report describes a case of a posterior oblique ligament (POL) bony avulsion fracture associated with an anterior cruciate ligament (ACL) tear in a 16-year-old female gymnast. The avulsion fracture was discovered on repeat radiographs and magnetic resonance imaging after the patient developed increased pain after ACL reconstruction. After excising the bony avulsion and repairing the POL, she reported complete resolution of her preoperative pain. CONCLUSION: Bony avulsion fractures of the POL are rare and challenging to diagnose. Awareness of this injury and the subtle imaging findings will help clinicians appropriately diagnose and treat these lesions.

Predictors of Mid- to Long-Term Outcomes in Patients Experiencing a Knee Dislocation: A Systematic Review of Clinical Studies.

Knee dislocations (KDs) are devastating injuries for patients and present complex challenges for orthopaedic surgeons. Although short-term outcomes have been studied, there are few long-term outcomes of these injuries available in the literature. The purpose of this study is to determine factors that influence mid- to long-term clinical outcomes following surgical treatment of KD. A review of the current literature was performed by searching PubMed, the Cochrane Library, and Embase to identify clinical studies published from 2010 to 2019 with a minimum 2-year follow-up that reported outcomes following surgical treatment of KDs. Ten studies (6 level III, 4 level IV) were included. At mid- (2-10 y) to long-term (>10 y) follow-up, concomitant arterial, cartilage, and combined meniscus damage were predictive factors for inferior Lysholm and International Knee Documentation Committee (IKDC) scores when compared with patients without these associated injuries. Although concomitant neurological damage may influence short-term outcomes due to decreased mobility, at longer follow-up periods it does not appear to predict worse clinical outcomes when compared with patients without concomitant neurological injury. Frank and polytrauma KDs have been associated with worse mid- to long-term outcomes when compared with transient and isolated KDs. Patients who underwent surgery within 6 weeks of trauma experienced better long-term outcomes than those who underwent surgery longer than 6 weeks after the initial injury. However, the small sample size of this study makes it difficult to make valid recommendations. Lastly, female sex, patients older than 30 years at the time of injury and a body mass index (BMI) greater than 35 kg/m2 are factors that have been associated with worse mid- to long-term Lysholm and IKDC scores. The results of this review suggest that female sex, age >30 years, BMI >35 kg/m2, concomitant cartilage damage, combined medial and lateral meniscal damage, KDs that do not spontaneously relocate, and KDs associated with polytrauma may predict worse results at mid- to long-term follow-up.

Hip decompression combined with bone marrow concentrate and platelet-rich plasma for corticosteroid-induced osteonecrosis of the femoral head : mid-term update from a prospective study.

AIMS: Bone marrow-derived mesenchymal stem cells obtained from bone marrow aspirate concentrate (BMAC) with platelet-rich plasma (PRP), has been used as an adjuvant to hip decompression. Early results have shown promise for hip preservation in patients with osteonecrosis (ON) of the femoral head. The purpose of the current study is to examine the mid-term outcome of this treatment in patients with precollapse corticosteroid-induced ON of the femoral head. METHODS: In all, 22 patients (35 hips; 11 males and 11 females) with precollapse corticosteroid-induced ON of the femoral head underwent hip decompression combined with BMAC and PRP. Mean age and BMI were 43 years (SD 12) and 31 kg/m² (SD 6), respectively, at the time of surgery. Survivorship free from femoral head collapse and total hip arthroplasty (THA) and risk factors for progression were evaluated at minimum five-years of clinical follow-up with a mean follow-up of seven years (5 to 8). RESULTS: Survivorship free from femoral head collapse and THA for any reason was 84% and 67% at seven years postoperatively, respectively. Risk factors for conversion to THA included a high preoperative modified Kerboul angle (grade 3 or 4) based on preoperative MRI (hazard ratio (HR) 3.96; p = 0.047) and corticosteroid use at the time of decompression (HR 4.15; p = 0.039). The seven-year survivorship for patients with grade 1 or 2 Kerboul angles for conversion to THA for articular collapse, and THA for any reason, were 96% and 72%, respectively, versus THA for articular collapse and THA for any reason in patients with grade 3 or 4 Kerboul angles of 40% (p = 0.003) and 40% (p = 0.032). CONCLUSION: At seven years, hip decompression augmented with BMAC and PRP provided a 67% survivorship free from THA in patients with corticosteroid-induced ON. Ideal candidates for this procedure are patients with low preoperative Kerboul angles and can stop corticosteroid treatment prior to decompression. Cite this article: Bone Jt Open 2021;2(11):926-931.

Bilateral total shoulder arthroplasty: A systematic review of clinical outcomes.

BACKGROUND: The purpose of this study was to describe the clinical outcomes following bilateral total shoulder arthroplasty (TSA). METHODS: A systematic search of the PubMed, Embase, and Cochrane Library databases following PRISMA guidelines was performed. English-language literature published from 2010 to 2018 analyzing bilateral TSA (anatomic and/or reverse) with a minimum one-year follow-up was reviewed by two independent reviewers. Study quality was evaluated with the Modified Coleman Methodology Score and the methodological index for non-randomized studies score. RESULTS: Eleven studies (1 Level II, 3 Level III, 7 Level IV) with 292 patients were included. Two studies reported on bilateral anatomic TSA (n = 54), six reported on bilateral reverse TSA (RTSA; n = 168), two reported on anatomic TSA with contralateral RTSA (TSA/RTSA; n = 31), and one compared bilateral anatomic TSA (n = 26) and bilateral RTSA (n = 13). Among studies, mean revision rate ranged from 0% to 10.53% and mean complication rate ranged from 4.9% to 31.3%. At final follow-up, patients experienced significant overall improvements in range of motion and patient-reported outcome score measurements. However, bilateral anatomic TSA resulted in greater improvements in external rotation compared to bilateral RTSA. Overall patient satisfaction was 91.0%. CONCLUSION: The available data indicate that bilateral TSA allows for functional and pain improvements and result in high patient satisfaction. LEVEL OF EVIDENCE: IV.

Fascia Iliaca Block for Postoperative Pain Control After Hip Arthroscopy: A Systematic Review of Randomized Controlled Trials.

BACKGROUND: Various analgesic modalities have been used to improve postoperative pain in patients undergoing hip arthroscopy. PURPOSE: To systematically review the literature to compare the efficacy of the fascia iliaca block (FIB) with that of other analgesic modalities after hip arthroscopy in terms of postoperative pain scores and analgesic consumption. STUDY DESIGN: Systematic review. METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase up to April 2020 to identify randomized controlled trials that compared postoperative pain and analgesic consumption in patients after hip arthroscopy with FIB versus other pain control modalities. The search phrase used was "hip arthroscopy fascia iliaca randomized." Patients were evaluated based on postoperative pain scores and total postoperative analgesic consumption. RESULTS: Five studies (3 level 1, 2 level 2) were identified that met inclusion criteria, including 157 patients undergoing hip arthroscopy with FIB (mean age, 38.3 years; 44.6% men) and 159 patients among the following comparison groups: lumbar plexus block (LPB), intra-articular ropivacaine (IAR), local anesthetic infiltration (LAI), saline placebo, and a no-block control group (overall mean age, 36.2 years; 36.5% men). No significant differences in pain scores were reported in the postanesthesia care unit (PACU) between the FIB and LPB (3.4 vs 2.9; P = .054), IAR (7.7 vs 7.9; P = .72), control group (no FIB: 4.1 vs 3.8; P = .76); or saline placebo (difference, -0.2 [95% CI, -1.1 to 0.7]). One study reported significantly higher pain scores at 1 hour postoperation in the FIB group compared with the LAI group (5.5 vs 3.4; P = .02). Another study reported significantly greater total analgesic consumption (in morphine equivalent dosing) in the PACU among the FIB group compared with the LPB group (20.8 vs 17.0; P = .02). No significant differences were observed in total PACU analgesic consumption between FIB and other analgesic modalities. CONCLUSION: In patients undergoing hip arthroscopy, the FIB does not appear to demonstrate superiority to other forms of analgesics in the immediate postoperative period. Therefore, it is not recommended as a routine form of pain control for these procedures.

Autogenous Arteriovenous Bundle Implantation Maintains Viability Without Increased Immune Response in Large Porcine Bone Allotransplants.

BACKGROUND: Transplantation of living allogeneic bone segments may permit reconstruction of large defects, particularly if viability is maintained without immunosuppression. Development of a new autogenous osseous blood supply accomplishes this goal in rodent experimental models. This study evaluates potential systemic and local inflammatory responses to this angiogenesis in a large-animal model. METHODS: Vascularized allogeneic tibia segments were transplanted orthotopically into matched tibial defects in Yucatan minipigs. Microvascular anastomoses of bone nutrient artery and vein were supplemented by intramedullary placement of an autogenous arteriovenous (AV) bundle in group 1. Group 2 served as a no-angiogenesis control. A 3-drug immunosuppression regimen was withdrawn after 2 weeks. During the 20-week survival period, periodic leukocyte counts and inflammatory cytokine levels were measured. Thereafter, osteocyte survival was quantified and transplant rejection graded by histologic examination and quantitative real-time polymerase chain reaction of immunologic markers. RESULTS: Both groups developed an initial systemic response, which resolved after 4 to 6 weeks. No differences were seen in blood cytokine levels. Interleukin 2 expression was diminished in group 1 tibiae. As expected, nutrient pedicles had thrombosed without sustained immunosuppression, occluded by intimal hyperplasia. In group 1, angiogenesis from the autogenous AV bundle resulted in significantly less osteonecrosis (P = .04) and fibrosis (P = .02) than group 2 allotransplants. CONCLUSIONS: Systemic immune responses to large-bone allotransplants were not increased by generation of an autogenous osseous blood supply within porcine tibial bone allotransplants. Implanted AV bundles diminished inflammation and fibrosis and improved bone viability when compared to no-angiogenesis controls.

Results of a randomised controlled trial between an ORC collagen hemostatic agent and a carrier-bound fibrin sealant.

INTRODUCTION: Despite ongoing optimisation of surgical techniques, hemostasis continues to be a fundamental challenge in many operations today. This randomised controlled trial compared the efficacy of a new hemostatic agent made of oxidised regenerated cellulose and collagen (ORC-Coll) with that of a conventional carrier-bound fibrin sealant (CBFS). METHODS: Hemostasis was investigated representatively in the case of post-thyroidectomy bleeding from the resection surface. To demonstrate that ORC-Coll (mediCipio® A) has at least the same hemostatic efficacy as CBFS (Tachosil®), the volume of drainage fluid at the time of drain removal was used as the primary endpoint in a non-inferiority test with a significance level of 5%. The secondary endpoints included number and size of hemostatic agents required, adhesion of the hemostatic agent to the bleeding surface, intraoperative hemostatic effect, duration of drainage and adverse events during a six-month follow-up period. RESULTS: A total of 150 patients (ORC-Coll: 75; CBFS: 75) were included. After operation, total volume of drainage fluid was 68.20±44.56mL in the ORC group and 68.21±40.20mL in the CBFS group. The non-inferiority of ORC-Coll compared to CBFS with regard to hemostatic efficacy was shown at a significance level of 5%. The results demonstrated effectiveness in achieving hemostasis without adverse events. CONCLUSIONS: ORC-Coll is an effective hemostatic agent and barrier sealant without blood components, which ensures reliable prevention of intra- and postoperative bleeding. With use of the new technique, any risks associated with the use of human blood components are a priori eliminated.

Use of the Patient-Reported Outcomes Measurement Information System (PROMIS) for Operative Shoulder Outcomes.

BACKGROUND: Few studies have investigated the relationship between the Patient-Reported Outcomes Measurement Information System (PROMIS) and legacy patient-reported outcome (PRO) measurements. PURPOSE: To compare patient-reported outcomes from the PROMIS physical function (PF) and upper extremity (UE) platforms against one another and against legacy PRO measurements to assess the potential strengths and weaknesses of the National Institutes of Health PROMIS initiative and expand on the use of PRO measurements in clinical orthopaedic practice. STUDY DESIGN: Systematic review; Level of evidence, 4. METHODS: A systematic search of the PubMed, Embase, and Cochrane Library databases was conducted following PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines. All English-language studies published between 2017 and 2019 using PROMIS to evaluate patients for shoulder surgery were analyzed. PROs were compared based on survey administered and the shoulder condition being investigated. Study quality was evaluated using the Modified Coleman Methodology Score and the Methodological Index for Non-Randomized Studies score. RESULTS: We included 9 studies (5 studies were level 2; 3 studies were level 3; 1 study was level 4) encompassing a total of 1130 patients (60.2% male; mean age, 52.6 ± 16.5 years; mean BMI, 29.8 ± 2.8 kg/m2). Of these, 6 studies administered the PROMIS PF, and 6 studies administered the PROMIS UE. The strongest correlation was between PROMIS PF computer adaptive test and the 36-Item Short Form Health Survey Global Health (SF-36 GH) (r = 0.75). The highest overall correlation with the PROMIS UE was found with the American Shoulder and Elbow Surgeons (ASES) Shoulder Score (r = 0.70). The lowest correlations were found between PROMIS PF and the Marx Shoulder Activity Scale (r = 0.08) and the PROMIS UE and the Marx Shoulder Activity Scale (r = 0.18). CONCLUSION: From available data, the PROMIS PF and PROMIS UE were most closely correlated with outcomes measured by the SF-36 GH. The PROMIS UE alone was most correlated with ASES Shoulder Score. Thus, either PROMIS PF or UE may provide a possible alternative to legacy PRO measurements but with a lower overall number of questions and higher generalizability. Future research should compare the time and question burden of the various PROMIS platforms with a more consistent evaluation of standard PRO measurements.

Adductor Canal Versus Femoral Nerve Block after Anterior Cruciate Ligament Reconstruction: A Systematic Review of Level I Randomized Controlled Trials Comparing Early Postoperative Pain, Opioid Requirements, and Quadriceps Strength.

PURPOSE: To systematically review the literature to compare the adductor canal block (ACB) with the femoral nerve block (FNB) following primary anterior cruciate ligament reconstruction (ACLR) in terms of early postoperative analgesic requirements and postoperative quadriceps strength. METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase up to August 2019 to identify randomized controlled trials that compared postoperative pain and functional outcomes in patients following primary ACLR with ACB versus FNB. The search phrase used was: adductor canal femoral nerve anterior cruciate ligament. Patients were evaluated based on analgesic consumption and quadriceps muscle strength. Study quality and risk of bias were evaluated with the Modified Coleman Methodology Score and Cochrane risk-of-bias tool respectively. RESULTS: Five studies (all Level I evidence) were identified that met inclusion criteria, including 221 patients undergoing primary ACLR with ACB (mean age 26.8 years, 68.3% male) and 221 with FNB (mean age 28.2 years, 67.0% male). Statistical assessment for heterogeneity found for opioid consumption of ACB versus FNB groups was I2 = 97% (P < .0001). There were no significant differences in analgesic consumption within the first 24 hours following surgery between groups except in 1 study, in which patients receiving ACB required significantly greater analgesics (P < .001). Three studies using 3 different techniques to measure strength found patients receiving ACB to have significantly greater quadriceps muscle function within 24 hours of surgery when compared with patients receiving FNB (P < .05). CONCLUSIONS: In patients undergoing ACLR, the ACB may provide similar analgesic requirements, and the included studies suggest a potential advantage in preserving muscle strength at short-term (24-48 hours) follow-up when compared with FNB. However, the differences in muscle strength assessments between studies do not allow for strong conclusions. LEVEL OF EVIDENCE: I, systematic review and meta-analysis of Level I studies.

Transplant chimerism in porcine structural vascularized bone allotransplants.

BACKGROUND: Bone allotransplant viability can be maintained long-term by implanting arteriovenous (AV) bundles and creating an autogenous neoangiogenic circulation. Only short-term immunosuppression is required. This study investigates the origin of viable osteocytes observed in areas of active bone remodeling in orthotopically transplanted tibiae in a Yucatan mini-pig model. METHODS: Segmental tibial defects created in female Yucatan minipigs (N = 14) were reconstructed with a matched vascularized composite allotransplant from a male donor. The circulation was microsurgically restored, with simultaneous autogenous AV-bundle implantation in group 1 (N = 7). A ligated AV-bundle was implanted as a no-angiogenesis control in group 2 (N = 7). After 20-weeks, repopulation of the allotransplant was assessed by real-time qPCR measurement of relative copy numbers of a Y chromosome-specific gene (SRY) and an autosomal housekeeping gene, ribosomal protein L4 (RPL4). A lower SRY/RPL4 ratio demonstrates replacement of male allogeneic cells with female, autogenous cells in the sample. Genomic DNA was extracted from cross-sections of the allotransplant, liver and spleen. Additionally, areas of new bone formation within the allotransplant were sampled by laser capture microdissection. A comparison was made between groups as well as male control samples. RNA was extracted from bone as well, as a measure of metabolically active cells. RESULTS: Laser-captured areas of new bone formation in animals with both normal and ligated AV-bundles were found to have significantly lower relative copy numbers of SRY (p = 0.03) than control specimens from male bone, indicating replacement by female (autogenous) bone-forming cells. Analysis of an entire segment of the allotransplant from Group 1 was similarly reduced (p = 0.04), unlike that from Group 2. RNA expression of SRY was observed in both groups. No chimerism could be found in non-bone tissues (liver and spleen). CONCLUSION: We observed a significant level of transplant chimerism in areas of new bone formation sampled by laser capture microdissection. The migration of autogenous cells including osteocytes was seen in both groups. Survival of some allogeneic (male) cells was also demonstrable. No microchimerism was found in liver and spleen.

Neo-Angiogenesis, Transplant Viability, and Molecular Analyses of Vascularized Bone Allotransplantation Surgery in a Large Animal Model.

Vascularized composite allotransplantation of bone is a possible alternative treatment for large osseous defects but requires life-long immunosuppression. Surgical induction of autogenous neo-angiogenic circulation maintains transplant viability without this requirement, providing encouraging results in small animal models [1-3]. A preliminary feasibility study in a swine tibia model demonstrated similar findings [4, 5]. This study in swine tibial allotransplantation tests its applicability in a pre-clinical large animal model. Previously, we have demonstrated bone vascularized composite allotransplantation (VCA) survival was not the result of induction of tolerance nor an incompetent immune system [1]. Fourteen tibia vascularized bone allotransplants were microsurgically transplanted orthotopically to reconstruct size-matched tibial defects in Yucatan miniature swine. Two weeks of immunosuppression was used to maintain allotransplant pedicle patency during angiogenesis from a simultaneously implanted autogenous arteriovenous bundle. The implanted arteriovenous bundle was patent in group 1 and ligated in group 2 (a neo-angiogenesis control). At twenty weeks, we quantified the neo-angiogenesis and correlated it with transplant viability, bone remodeling, and gene expression. All patent arteriovenous bundles maintained patency throughout the survival period. Micro-angiographic, osteocyte cell count and bone remodeling parameters were significantly higher than controls due to the formation of a neo-angiogenic autogenous circulation. Analysis of gene expression found maintained osteoblastic and osteoclastic activity as well as a significant increase in expression of endothelial growth factor-like 6 (EGFL-6) in the patent arteriovenous bundle group. Vascularized composite allotransplants of swine tibia maintained viability and actively remodeled over 20 weeks when short-term immunosuppression is combined with simultaneous autogenous neo-angiogenesis. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:288-296, 2020.

Outcomes of Vascularized Bone Allotransplantation with Surgically Induced Autogenous Angiogenesis in a Large Animal Model: Bone Healing, Remodeling, and Material Properties.

BACKGROUND: Bone vascularized composite allotransplantation (VCA) is a possible alternative for the treatment of large bone defects. Clinical application of VCAs is limited by the need for life-long immunosuppression (IS). We report an alternative method to maintain bone allotransplant viability in a large animal model without the need for life-long IS by using autogenous vessel implantation. METHODS: Fourteen bone only VCAs were transplanted in a porcine tibia defect model with short-term IS. Two groups were used to evaluate the effect of the implantation of an autogenous arteriovenous (AV)-bundle, therefore the only difference between the groups was the patency of the AV-bundle. We radiographically evaluated bone healing and allogenic pedicle patency. AV-bundle patency and union were evaluated with micro-CT. Bone remodeling was assessed with histomorphometry and material properties were evaluated with axial compression testing and cyclic reference point indentation. RESULTS: Two subjects did not reach the final time point. Twelve tibiae healed proximally, and nine at the distal transplant-bone interface. Bone allotransplants showed their viability in the first 4 to 6 weeks by significant periosteal bridging arising from the transplant and maintained pedicle patency. Bone material properties were not affected by the implantation of an AV-bundle when compared with ligated AV-bundle controls, but diminished compared with normal bone. Significantly higher bone formation rates resulted from the implantation of a patent AV-bundle. CONCLUSION: New periosteal bone formation and subsequent bone healing result from blood flow through the microsurgically repaired nutrient blood supply, demonstrated by maintained allogenic pedicle patency. The implantation of a patent autogenous AV-bundle has no adverse effect on material properties, but a positive effect on bone remodeling of endosteal surfaces despite thrombosis of the allogenic pedicle. Bone material properties change after transplantation compared with normal bone, although 20-weeks survival time is relatively short for the final evaluation of bone material properties.

Combined Massive Allograft and Intramedullary Vascularized Fibula as the Primary Reconstruction Method for Segmental Bone Loss in the Lower Extremity: A Systematic Review and Meta-Analysis.

BACKGROUND: Reconstruction of segmental bone loss due to malignancy, infection, or trauma is a challenge for the reconstructive surgeon. The combination of a vascularized fibular flap with a cortical allograft provides a reliable reconstructive option in the lower extremity. In this systematic review, we describe the outcome of this technique for the treatment of segmental bone loss. METHODS: A systematic review was performed on the use of a combined massive allograft and intramedullary vascularized fibula as a reconstruction method for large bone defects. We used PubMed, Embase, and the Wiley Cochrane Library. RESULTS: Seventeen clinical articles were included between 1997 and 2017, reporting 329 cases of lower-extremity reconstructions. A meta-analysis was performed on primary union rates. The main outcome measures were primary union rate, complication rate, reintervention rate, and function after reconstruction. All publications showed relatively high complication (5.9% to 85.7%) and reintervention rates (10% to 91.7%) with good primary union rates (66.7% to 100%) and functional outcome (range of mean Musculoskeletal Tumor Society [MSTS] scores, 24 to 29 points). CONCLUSIONS: The combination of a massive allograft with intramedullary vascularized fibula provides a single-step reconstruction method for large bone defects (>6 cm) in the lower extremity, with good long-term outcomes. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Five-Strand Hamstring Autografts for Anterior Cruciate Ligament Reconstruction: A Systematic Review.

BACKGROUND: Recent studies have described surgical techniques to increase the hamstring graft diameter for anterior cruciate ligament reconstruction (ACLR), particularly for 5-strand hamstring (5HS) autografts. PURPOSE: To review the literature examining the biomechanical and clinical outcomes of 5HS autografts for ACLR. STUDY DESIGN: Systematic review; Level of evidence, 3. METHODS: A systematic review using PRISMA (Preferred Reporting Items for Systematic Meta-Analyses) guidelines was performed by searching PubMed, Embase, and the Cochrane Library for studies reporting the biomechanical and clinical outcomes of 5HS autografts. All English-language literature published from 2012 to 2018 that reported the biomechanical properties of 5HS grafts and/or clinical outcomes after ACLR with 5HS autografts with a minimum 1-year follow-up was reviewed by 2 independent reviewers. Graft diameter, stiffness, displacement, strength, failure rates, anteroposterior knee laxity, and patient-reported outcome scores were collected. The study methodology was evaluated using the modified Coleman Methodology Score. RESULTS: Two biomechanical and 3 clinical studies (1 with level 2 evidence, 2 with level 3 evidence) were included. The biomechanical studies compared the results of fourteen 4-strand hamstring (4HS) and fourteen 5HS graft specimens for ACLR (ovine grafts, n = 12; cadaveric grafts, n = 16) and found no significant differences in ultimate load, stiffness, displacement, and stress relaxation (P > .05), likely attributed to insufficient incorporation of the fifth strand. The mean 5HS cadaveric graft diameter (8.2 mm) was significantly greater than that of 4HS grafts (6.8 mm) (P = .002), whereas the mean ovine graft diameters were not significantly different (4HS, 5.2 mm; 5HS, 5.3 mm) (P > .05). Two clinical studies compared the outcomes after ACLR of 53 patients with a 4HS autograft versus 62 patients with a 5HS autograft, while 1 clinical study reported the outcomes of 25 patients after ACLR with a 5HS autograft (mean age, 28.7 years; mean follow-up, 24.8 months). The overall mean diameter for 4HS and 5HS autografts was 8.4 and 9.1 mm, respectively. There was no significant difference in failure rates between 4HS and 5HS autografts (P = .82). None of the comparative studies reported significant differences in any clinical outcomes (P > .05 for all). CONCLUSION: The available literature on traditional 4HS and 5HS autografts for ACLR is limited. Of the available data, clinical and biomechanical studies suggest no difference in outcomes after ACLR with either graft construct. Additional research is needed to determine whether creating a 5HS graft is beneficial.