Graft Fixation Research Articles

Comparison of Fixation and Uptake of Split Skin Graft Using Autologous Platelet Rich Plasma with Conventional Method for Ulcer

Platelet Rich Plasma contains a major Growth factor and has adhesive and healing properties. PRP promotes angiogenesis, collagen synthesis, and wound healing. The main aim of this study is to compare the efficacy of SSG fixation using autologous platelet-rich plasma with the conventional method like suturing. In this study, patients who were admitted with a diagnosis of ”ulcer” in the General Surgery department in SRM medical college hospital and research centre were included and would be taken as subjects for this study. It is a randomized, controlled study with a sample size of 60. Thirty people were put in the autologous PRP group, and another 30 people were put in the suture group. Instant graft uptake of SSG to the ulcer was statistically significant in the PRP group. The seroma formation, the number of dressings and the period of hospital stay were comparatively increased in the suture group than in the PRP. The usage of PRP is secure and efficient in healing ulcer. It has been discovered to be very advantageous in many ways for both the patient and the surgeon. Based on what we found, we recommend using autologous PRP on wounds before resurfacing to help them heal better and faster than suturing.

Lateral Extra-Articular Tenodesis Staple Risks Penetration of Anterior Cruciate Ligament Reconstruction Tunnel

To identify the risk of anterior cruciate ligament (ACL) femoral tunnel penetration with the use of a staple for lateral extra-articular tenodesis (LET) graft fixation and to determine whether this varied between 2 different techniques for ACL femoral tunnel drilling. Twenty paired, fresh-frozen, cadaver knees underwent ACL reconstruction with a LET. Left and right knees were randomized to ACL reconstruction with femoral tunnel creation by use of either a rigid guide pin and reamer through the accessory anteromedial portal or by the use of a flexible guide pin and reamer through the anteromedial portal. Immediately after tunnel creation, the LET was performed and fixated with a small Richard's staple. Fluoroscopy was used to obtain a lateral view of the knee to determine staple position, and visualization of the ACL femoral tunnel was performed with the arthroscope to investigate penetration of the staple into the femoral tunnel. The Fisher exact test was conducted to determine whether there was any difference in tunnel penetration between tunnel creation techniques. The staple was noted to penetrate the ACL femoral tunnel in 8 of 20 (40%) extremities. When stratified by tunnel creation technique, the Richards staple violated 5 of 10 (50%) of the tunnels made via the rigid reaming technique compared with 3 of 10 (30%) of those created with a flexible guide pin and reamer (P= .65). A high incidence of femoral tunnel violation is seen with lateral extra-articular tenodesis staple fixation. Level IV, controlled laboratory study. The risk of penetrating the ACL femoral tunnel with a staple for LET graft fixation is not well understood. Yet, the integrity of the femoral tunnel is important for the success of ACL reconstruction. Surgeons can use the information in this study to consider adjustments to operative technique, sequence, or fixation devices used when performing ACL reconstruction with concomitant LET to avoid the potential for disruption of ACL graft fixation.

The Functional Outcomes of Scaphoid Nonunion with Deformity Treated with Anterior Wedge Bone Grafting: A Case Series

Introduction. Scaphoid nonunion is one of the most difficult fractures to treat. Restoration of carpal alignment and fracture stability can provide good outcomes in the management of scaphoid nonunion.
 Objective. The purpose of this study was to determine the functional outcomes of scaphoid nonunion associated with humpback deformity treated with anterior wedge bone grafting and internal fixation.
 Methods. A retrospective review of all patients with scaphoid nonunion treated with anterior wedge bone grafting from January 1, 2014 to December 31, 2019 was done. Outcome measurements were time to union, pre- and postoperative FIL-DASH scores, grip, pinch, and scapholunate angle improvement. The other outcome measures were pain and complications.Results. A total of 12 patients were included in the study. All were males with an average age of 27.4 years (SD,9.6). The average delay to surgery was 9.5 months (SD, 10). All fractures were at the waist, except for three proximal pole fractures, none had established avascular necrosis. Eleven out of 12 scaphoids healed at an average of 11.5 weeks (SD, 3.2). There was a significant improvement in the FIL-DASH score and scapholunate angle after surgical reconstruction. Grip strength averaged 83% of the contralateral side. All returned to previous normal activities. One patient with persistent proximal pole nonunion was managed with a 4-corner arthrodesis.Conclusion. Anterior wedge bone grafting for scaphoid nonunion restored the scapholunate angle and was able to establish union in 11 of 12 scaphoid nonunions with good outcomes.

Dermal Tuberoplasty for Irreparable Supraspinatus Tears Using Self-Punching, Knotless Fixation

Superior capsular reconstruction has become an accepted treatment option for the irreparable rotator cuff tear in the nonarthritic shoulder. Widespread adoption of this technique has been limited, however, because of the technical difficulty of performing this procedure. Recently, allograft interpositional grafting of the greater tuberosity has gained popularity as a simpler alternative to superior capsular reconstruction and provides similar joint preservation advantages. We describe a technique for allograft interpositional tuberoplasty that simplifies graft delivery, graft fixation, and suture management by using a graft inserter and self-punching, knotless soft anchors.

Combined Reconstruction of the Medial Patellofemoral Ligament and Medial Quadriceps Tendon Femoral Ligament in Skeletally Immature Patients

The medial patellofemoral ligament (MPFL) reconstruction is challenging in skeletally immature patients due to the anatomical particularities at this age. Recently, the medial quadriceps tendon femoral ligament (MQTFL) has received great interest for its ability to restrain the patella’s instability along with MPFL. No gold-standard technique has been described so far to reconstruct both MPFL and MQTFL in skeletally immature patients. We present a technique to safely reconstruct the MPFL and the MQTFL in children and adolescents. The gracilis tendon autograft is harvested and passed through the medial collateral ligament as a pulley. The free ends of the graft are passed through the patella by an “L-shaped tunnel” and tied to itself. The other free end of the graft is pulled through the medial third of the quadriceps tendon and tied to itself to achieve tension. Our technique is reproducible, implant-free and avoids complications associated with femoral drilling and graft fixation. However no long-term follow-up results are available.

Patellar dislocation recurrence after pediatric MPFL reconstruction: Bone tunnels and soft tissues versus suture anchors and interference screw

BackgroundSeveral Medial Patellofemoral Ligament (MPFL) reconstruction techniques have been developed, and those with soft tissue fixation are often preferred in children because they allow the growth cartilage to be preserved. Nevertheless, the recurrence rate of patellar dislocation varies widely from one series to another, with no clear superiority of one technique in the pediatric setting. The objectives of this study were to compare the results of two tendon graft fixation techniques (tendon-tendon fixation and anchor-screw fixation) by analyzing: 1) the rate of patellar dislocation recurrence, 2) clinical outcomes, 3) tourniquet time and 4) complication rate. HypothesisThe two tendon graft fixation techniques used in MPFL reconstruction are equivalent in terms of the patellar dislocation recurrence rate. Patients and methodsThis is a retrospective comparative study including 57 patients with a median age of 14 years (12–15 years) who underwent MPFL reconstruction between 2016 and 2020. The tendon graft was fixed upon itself, after passing through a patellar tunnel (Group A: tendon-tendon fixation; n=29) or by two anchors and an interference screw (Group B: anchor-screw fixation; n=28). The preoperative radiographic data were comparable in the two groups: patellar height [A: 1.3 (interquartile range (IQR): 1.2–1.4) / B: 1.2 (IQR: 1–1.4) (p=0.21)], tibial tuberosity to trochlear groove (TTTG) distance [A: 16 (IQR: 13–19) / B: 13.5 (IQR: 11.5–18.8) (p=0.12)], patellar tilt [A: 25 (IQR: 20–35) / B: 24.5 (IQR: 21–32) (p=0.93)]. For each technique, the rate of patellar dislocation recurrence, clinical and functional results (Kujala score, Marx activity score, Lille patellofemoral score), complications (pain, stiffness, revision) were analyzed. In addition to MPFL repair, 13 patients (2 in Group A, 11 in Group B) underwent additional orthopedic procedures to enhance patellar stability. Resultsno patients were lost to follow-up and the median follow-up was 30 months (IQR: 20–38). The dislocation recurrence rate was higher in Group A, 6.9% (2/29) compared to none in Group B. The clinical results were comparable for the two groups with a Kujala score [A: 94 (IQR: 89–100) / B: 92 (IQR: 87.5–94.5) (p=0.12)]; Marx score [A: 10 (IQR: 7–11) / B: 9.5 (IQR: 7.5–12) (p=0.89)] and Lille patellofemoral score [A: 97 (IQR: 91–100) / B: 94 (IQR: 90–98) (p=0.21)]. The tourniquet time was shorter in Group A than in Group B, 61minutes (IQR: 52-71) versus 85minutes (IQR: 55-115) (p=0.024) excluding additional orthopedic procedures. The complication rate was 17.2% (5/29) in Group A (dislocation n=2, stiffness n=2, ATT (anterior tibial tuberosity) revision with screw removal n=1) and 10.7% (3/28) in B (pain n=1, ATT revision with screw removal n=2) (p=0.35). ConclusionClinically, anchor-screw fixation appears to reduce the risk of patellar dislocation recurrence but this could not be statistically tested. On the other hand, the two techniques are comparable in terms of the functional results. Level of evidenceIII; retrospective case-control study.

Comparative Study Between Closed Reduction Internal Fixation Alone Versus Closed Reduction Internal Fixation and Addition of Muscle Pedicle Bone Graft for Prevention of Osteonecrosis in Cases of Displaced Femoral Neck Fractures.

In patients of less than 60years of age, osteosynthesis is the treatment of choice for displaced femoral neck fractures (Garden 3 and 4). Most of these fractures unite well but chances of osteonecrosis are quite high even after early operations and till date there is no well-defined method of prediction and prevention of osteonecrosis. Vascularized bone graft may prevent the development of osteonecrosis. This is a retrospective case control study done in an urban Medical College in eastern India and tried to evaluate efficacy of addition of quadratus femoris muscle pedicle bone graft in cases of osteosynthesis comparing the results of cases treated with closed reduction and internal fixation alone for femoral neck fractures We have taken into consideration 45 consecutive cases from each group with identical demographic background and of very similar age pattern of 20years to 60years.For further reference, we will describe Group I for closed reduction and CHS/DHS only, and Group II for closed reduction CHS and quadratus femoris muscle pedicle graft. Satisfactory bony union occurred in 42 out of 45 follow-up patients in Group 1 (93.3%) and 43 out of 45 patients in Group 2. (95.5%) In 2- to 10-year follow-up period, eight patients (18.6%) developed osteonecrosis in Group I, and in Group 2, in the same period, there were no cases of osteonecrosis. Addition of quadratus femoris muscle pedicle bone graft is a very effective procedure for prevention of osteonecrosis when we attempt osteosynthesis by closed reduction and internal fixation for displaced femoral neck fractures.

Comparison of Clinical and Radiographic Outcomes According to the Presence or Absence of a Posterior Draw Force during Graft Fixation in Anterior Cruciate Ligament Reconstruction.

Background and Objectives: A reduction forced toward the posterior side during graft fixation may help to lessen anterior tibial translation after ACL reconstruction. The purpose was to compare the clinical and radiological outcomes of graft fixation when a posterior draw was used and when it was not used during anterior cruciate ligament (ACL) reconstruction surgery. Materials and Methods: Of 110 patients who had undergone primary arthroscopic ACL reconstruction between January 2017 and August 2020, in all, 76 patients had been operated on without a posterior draw (non-draw group), and 34 patients had received surgery with a posterior draw (draw group). The results of the Lachman test and the pivot-shift test, the Western Ontario and McMaster Universities Osteoarthritis (WOMAC) indexes, the Lysholm scores, the International Knee Documentation Committee (IKDC) subjective scores, and side-to-side difference (STSD) on stress radiography were compared between the two groups. Results: The postoperative WOMAC indexes, Lysholm scores, and IKDC subjective scores were similar across both groups. Postoperative STSD (2.4 ± 2.2 for the non-draw group vs. 2.0 ± 2.2 for the draw group; p = 0.319) and change in STSD (3.5 ± 3.5 for preoperative STSD vs. 4.3 ± 4.4 for postoperative STSD; p = 0.295) were not superior in the draw group. Conclusions: The take-home message is that graft fixation with a posterior draw during ACL reconstruction did not result in significantly better postoperative stability. The postoperative clinical outcomes were similar between both groups.

A Biomechanical Comparison of 2 Over-the-Top Anterior Cruciate Ligament Reconstruction Techniques: A Cadaveric Study Using a Robotic Simulator.

For skeletally immature patients, over-the-top (OTT) anterior cruciate ligament (ACL) reconstruction (ACLR) is preferred. However, increased anterior laxity at deep knee flexion angles remains concerning. We modified the procedure to proximally shift the graft fixation site on the femur to prevent graft loosening at higher knee flexion angles and named it the supra-OTT procedure. To compare anterior laxity and in situ forces of the ACL graft between conventional OTT and supra-OTT ACLR in a cadaveric model. Controlled laboratory study. A total of 11 fresh-frozen cadaveric knee specimens underwent 4 robotic testing conditions: ACL intact, ACL resected, conventional OTT, and supra-OTT. For each condition, a 100-N load was applied at 0°, 15°, 30°, 60°, and 90° of knee flexion to simulate the Lachman test or anterior drawer test. In addition, a combined load of 5-N·m internal tibial torque and 10-N·m valgus torque was applied at 15° and 30° of knee flexion as a simulated pivot-shift test. Anterior tibial translation and in situ graft forces were recorded. The only difference between conventional OTT and supra-OTT ACLR was the graft fixation site on the femur. For conventional OTT ACLR, graft fixation was performed just on the proximal and lateral ends of the posterior condyle. For supra-OTT ACLR, the fixation point was around the proximal insertion of the lateral head of the gastrocnemius and the lateral edge of the posterior cortex, approximately 2 cm proximal to the conventional OTT position. On the simulated anterior drawer test at 60° and 90° of knee flexion, anterior tibial translation after supra-OTT ACLR was significantly smaller than after conventional OTT ACLR (P < .01). However, no significant differences were noted at other flexion angles or on the simulated pivot-shift test between the conventional OTT and supra-OTT procedures. Some overconstraint and higher graft forces were noted with both techniques, but the supra-OTT technique caused even more overconstraint at higher flexion angles. Supra-OTT ACLR showed better biomechanical performance to control anterior laxity than conventional OTT ACLR at higher knee flexion angles. The supra-OTT procedure may improve anterior stability at deep knee flexion angles.

A review of current approaches for decellularization, sterilization, and hemocompatibility testing on xenogeneic pericardium

Decellularization, sterilization, and hemocompatibility are the main areas for biomaterials evaluation when the material is designed for medical implants. The glutaraldehyde fixation of xenogeneic pericardium graft is not fully capable of preventing implant rejection in the recipient. The decellularization process removes the cellular components from organs or tissue to form an extracellular matrix as a structural template, and this template can be used for tissue engineering applications. The decellularization can be performed by chemical, enzymatic or physical, or a combination of methods. Sterilization and hemocompatibility are essential for medical devices that come into contact with blood. The different sterilization treatments include gamma radiation, freeze-drying, ethylene oxide, peracetic acid, antibiotics, and ethanol. In this context, this study reviews the three major areas of decellularization, sterilization, and hemocompatibility of xenogeneic pericardium for tissue engineering applications. In this study, a brief overview of recent decellularization approaches and combinations such as chemical method, chemical and enzymatic method, and the physical and chemical method used to remove cellular material from the pericardium are discussed. In the different sterilization techniques, the sterilization efficiency and post sterilization results obtained by various research groups on pericardium scaffolds are discussed. Also, this review deals with in vitro hemocompatibility testing such as hemolysis, platelet adhesion, coagulation system, and activation of leucocytes for xenogeneic biomaterials.

Treatment of severe medial tibial bone defect in primary total knee arthroplasty with autogenous bone graft and plate fixation

To explore the technique of autogenous bone graft combined with plate fixation in total knee arthroplasty(TKA) with severe proximal medial tibial bone defect. From March 2012 to October 2018, 21 patients (9 males and 12 females) with severe bone defects in the proximal medial tibia during primary total knee arthroplasty were treated with autogenous structural bone grafting and steel plate fixation, with an age of 61 to 77 years old with an average of (69.6±9.1) years and a course of 64 to 257 months with an average of (73.6±170.7) months. According to Rand classification, there were 13 cases of type Ⅲb and 8 cases of type Ⅳb. Postoperative complications were observed, and knee joint function was evaluated by the Hospital for Special Surgery (HSS) score and SF-36 quality of life score. All 21 patients were followed up for 37 to 64 months with an average of (49.5±13.7) months. The incisions of all patients healed smoothly, and 2 patients developed lower limb intermuscular venous plexus thrombosis after operation. There were no periprosthetic infection, loosening of prosthesis and other complications. The autogenous bone grafts of all patients achieved bony healing during postoperative X-ray follow-up, and the healing time was 8 to 13 months with an average of (10.1±2.3) months. The HSS score of patients increased significantly from 30 to 48 with an average of (53.4±4.2) before operation to 75 to 92 with an average of (81.2±8.4) at the final follow-up (P<0.05). The SF-36 quality of life score of patients after operation was significantly different from that before operation (P<0.05). The technique of autogenous bone graft combined with steel plate fixation can achieve satisfactory osseointegration effect in the treatment of severe proximal tibial bone defects in primary knee arthroplasty, with less complications and obvious improvement in knee function.

Simultaneous Arthroscopic Anterior Cruciate Ligament Reconstruction Using Double Suspensory Technique and Medial Open-Wedge, High Tibial Osteotomy

Anterior cruciate ligament reconstruction (ACLR) is generally performed regardless of knee malalignments. However, there are some indications for either staged or simultaneous ACL reconstruction and realignment procedures, such as high tibial osteotomy (HTO). Simultaneous HTO-ACL reconstruction has the apparent benefit of a single surgical procedure with a faster recovery than a staged procedure, and it produces good clinical outcomes. Several techniques have been described for simultaneous ACLR and medial open wedge HTO. The tibial tunnel preparation and graft fixation are the most challenging part of the procedure. Recent studies on comparison of fixation of tibial tunnel graft using suspensory fixation versus bioabsorbable screws have shown superior results of more bone preservation and less graft rupture. We assumed suspensory fixation on the tibial side with bone preservation might be more reliable in patients who received ACLR and open wedge HTO at the same time. Therefore, we described our technique of simultaneous open-wedge HTO and ACLR using double suspensory graft fixation.

Graft Intra-Articular Remodeling and Bone Incorporation in ACL Reconstruction: The State of the Art and Clinical Implications.

The knee is one of the most frequently affected joints in sports trauma, and anterior cruciate ligament (ACL) injury and meniscal tears are the most common lesions. ACL reconstruction (ACLR) remains the treatment of choice for patients willing to return to their previous activity. There are different surgical techniques and different possible usable grafts. The graft used for ACLR surgery undergoes a bone incorporation process and an intra-articular remodelling named ligamentization until it reaches characteristics similar to the native ligament. After the first incorporation stage, the remodelling process is divided into an early stage that could last 4 weeks, a proliferative stage that lasts 4 to 12 weeks, and a final stage of ligamentization that could last over 1 year. The period of return to sport (RTS) after ACLR, which is becoming shorter and shorter, can be a high-risk period for athletes due to the risk of graft failure. This systematic review aims to define the phases of the ligamentization process considering graft type and fixation techniques, as well as the graft's anatomopathological and biomechanical characteristics, to evaluate a criterion-based rehab progression and maximize patient outcomes for an RTS respecting graft biology. The rehabilitative program has to promote and optimize the graft remodelling and incorporation processes; moreover, it has to accommodate physiological graft healing and avoid overloading. An early RTS and noncompliance with the biological characteristics of the graft in the various phases are associated with a high incidence of re-injury.

Evaluation of the Optimal Femoral Fixation Site for Medial Patellofemoral Ligament Reconstruction in the Skeletally Immature Patient.

The aim of this study was to assess which femoral fixation site, distal to the physis, most closely emulates the native medial patellofemoral ligament (nMPFL) length relationship in the pediatric knee. Lateral knee radiographs were taken incrementally, from 0° to 120° of flexion. The femoral origin of the nMPFL and 3 other MPFL femoral fixation sites distal to the physis were identified (P1, 1 cm distal to physis along the posterior femoral cortex; P2, 2 cm distal to physis along the posterior femoral cortex; P3, 1 cm distal and 1 cm anterior). Virtual MPFL lengths were measured from all sites. Measurement reliability was assessed using intraclass correlation coefficients. Primary comparison between simulated MPFL length at native and femoral fixation sites was made using a repeated measures analysis of variance at 30° flexion. Bivariate Pearson correlation was used to assess the relationship between fixation sites and nMPFL through the range of motion (alpha=0.05). The intra-class correlation coefficient for intraobserver reliability of MPFL length measurement was excellent. Analysis of variance showed virtual MPFL lengths from proposed femoral fixation sites at 30° were significantly different from nMPFL length (P<.01). The P1 MPFL had the least difference in means compared with nMPFL (-2.6±1.8 mm). Correlational analysis showed that P1 MPFL had the closest relationship with nMPFL compared with other femoral fixation sites (R=0.91, P<.01). The P1 MPFL had the length change most comparable to that of nMPFL (23.9±3.1 mm vs 13.3±2.85 mm) compared with the other simulated MPFLs. Femoral graft fixation site 1 cm distal to the physis in the lateral view along the posterior femoral cortex closely represents the length relationship of the nMPFL. [Orthopedics. 2023;46(2):108-113.].

Mid-Term Outcomes of the All-Soft Quadriceps Tendon Autograft Are Noninferior to Hamstring Autograft in Primary Anterior Cruciate Ligament Reconstruction: Comparison With Minimum 5-Year Follow-Up

The purpose of this study was to compare the 5-year clinical and functional outcomes of the soft tissue quadriceps tendon (QT) to those of the hamstring tendon (HT) autograft METHODS: A retrospective review of patients undergoing ACL reconstruction using either soft tissue QT or double tendon HT autograft with at least 5 years of follow up was conducted. Surgical technique included anteromedial portal creation for the femoral tunnel and transtibial technique for the tibia. Graft fixation was achieved with interference composite screws for the QT and combination of interference composite screw and suture button for the HT cohort. The two groups were compared for differences in outcomes including International Knee Documentation Committee (IKDC) score, Lysholm score, return to sport, and complications. A total of 37 patients with QT autograft and 46 HT autografts were included in the study with a mean follow up of 69.9 months and 70.9 months, respectively. The QT group demonstrated a larger graft size on average (9.64mm vs. 7.90mm, p <0.001). The IKDC and Lysholm scores were similar between the two groups at 2-years postoperatively. At 5-years postoperatively, the QT group demonstrated significantly greater IKDC (p 0.018) and Lysholm (p 0.007) scores. The cohorts demonstrated similar rates of achieving minimal clinically important difference (MCID) thresholds at both 2 and 5 years postoperatively. The two groups also demonstrated comparable rates of return to sport, time to return, and postoperative complications. Although the QT autograft demonstrated increased patient reported outcome scores when compared to the HT at 5-years postoperatively, there was no clinically significant difference between the cohorts at 2 or 5 years postoperatively. The QT autograft is an effective alternative to HT autograft with non-inferior results to the hamstring autograft at mid-term follow up. Retrospective Comparison Study; Level of Evidence III LEVEL OF EVIDENCE: III, retrospective cohort study.

Superior Capsule Reconstruction Using Acellular Dermal Allograft Secured at 45° of Glenohumeral Abduction Improves the Superior Stability of the Glenohumeral Joint in Irreparable Massive Posterosuperior Rotator Cuff Tears

The purpose of the current study was to create a dynamic cadaveric shoulder model to determine the effect of graft fixation angle on shoulder biomechanics following SCR and to assess which commonly used fixation angle (30° vs 45° of abduction) results in superior glenohumeral biomechanics. Twelve fresh-frozen cadaveric shoulders were evaluated using a dynamic shoulder testing system. Humeral head translation, subacromial and glenohumeral contact pressures were compared among 4 conditions: 1) Intact, 2) Irreparable supra- and infraspinatus tendon tear, 3) SCR using acellular dermal allograft (ADA) fixation at 30° of abduction, and 4) SCR with ADA fixation at 45° of abduction. SCR at both 30° (0.287 mm, CI:-0.480 - 1.05 mm; P < .0001) and 45° (0.528 mm, CI:-0.239-1.305 mm; P= .0006) significantly decreased superior translation compared to the irreparably torn state. No significant changes in subacromial peak contact pressure were observed between any states. The average glenohumeral contact pressure increased significantly following creation of an irreparable RCT (373 kPa, CI: 304-443 vs 283 kPa, CI 214-352; P= .0147). The SCR performed at 45° (295 kPa, CI: 226-365, P= .0394) of abduction significantly decreased the average glenohumeral contact pressure compared to the RCT state. There was no statistically significant difference between the average glenohumeral contact pressure of the intact state and SCR at 30° and 45°. SCR improved the superior stability of the glenohumeral joint when the graft was secured at 30° or 45° of glenohumeral abduction. Fixation at 45° of glenohumeral abduction provided more stability than did fixation at 30°. Grafts attached at 45° of glenohumeral abduction biomechanically restore the glenohumeral stability after SCR using ADA better than fixation at 30° of glenohumeral abduction.

The Biomechanical Stability of Bone Staples in Cortical Fixation of Tendon Grafts for Medial Collateral Ligament Reconstruction Depends on the Implant Design

Background: The promising biomechanical stability of bone staples (BSs) in cortical fixation of tendon grafts for medial collateral ligament (MCL) reconstruction has been revealed by a previous investigation. However, it is currently unknown if the biomechanical stability of cortical fixation of tendon grafts depends on the BS design. Purpose: To assess the biomechanical stability of cortical fixation of tendon grafts in knee surgery using 4 different BS designs. Study Design: Controlled laboratory study. Methods: Cortical fixation of tendon grafts was performed in a porcine knee model at the tibial insertion area of the MCL using 4 different BS designs (n = 40): 8-mm width without spikes (n = 10), 8-mm width with spikes (n = 10), 14-mm width with spikes (n = 10), and 13 mm–wide 4-prong staples with spikes (n = 10). Specimens were mounted in a materials testing machine, and cyclic loading was applied to the tendon graft (500 cycles at 50 and 100 N, respectively), followed by load-to-failure testing. The Kruskal-Wallis test was performed for statistical analysis (P < .05), and the post hoc Dunn test was performed for multiple comparisons. Results: In 4 of 10 specimens with graft fixation using BSs without spikes, slippage of the tendon underneath the BS led to failure of the construct during cyclic loading to 100 N. In the other groups, no fixation failure was observed during cyclic loading. Furthermore, graft fixation using BSs without spikes was found to have significantly more elongation during cyclic loading (8.2 ± 1.9 mm) and a lower ultimate failure load (170 ± 120 N) compared with graft fixation using narrow BSs with spikes (3.4 ± 1.2 mm [P < .0001] and 364 ± 85 N [P < .05], respectively) and graft fixation using broad BSs with spikes (4.5 ± 1.4 mm [P < .05] and 429 ± 67 N [P < .001], respectively). No statistical differences in elongation during cyclic loading or ultimate failure load were found between 4-prong staples with spikes (5.0 ± 1.3 mm and 304 ± 85 N) and narrow or broad staples with spikes. Conclusion: The biomechanical stability of cortical fixation of an MCL graft was comparable between each BS design with spikes (narrow, broad, and 4-prong) in a porcine knee model, whereas BSs without spikes led to failure of the fixation construct during cyclic loading in 4 of 10 specimens and increased elongation and lower ultimate failure loads in the remainder of the group. BSs without spikes may therefore not be recommended for graft fixation. Clinical Relevance: The use of BSs can help to avoid the conflict of converging tunnels in multiligament reconstruction surgery. An implant design with spikes yields significantly higher biomechanical stability than BSs without spikes.

Mechanical Evaluation of Salvage Fixation Techniques for a Lateralized Fibular Tunnel in Posterolateral Corner Reconstruction of the Knee.

Posterolateral corner (PLC) reconstruction of the knee involves precise drilling of a single tunnel from anterolateral to posteromedial in the fibular head (FH) to ensure adequate graft fixation. Misplacement of the tunnel in a too lateral or too superior trajectory can lead to cortical breach and inadequate graft fixation. To (1) determine the mechanical consequence of a lateralized FH tunnel in PLC reconstruction and (2) compare the mechanical strength of 3 salvage fixation techniques for a lateralized FH tunnel. Controlled laboratory study. Sawbones models of a uniform density were utilized. FH tunnels (7-mm diameter) were drilled from anterolateral to posteromedial in positive controls (lateral cortex thickness, 7.6 ± 0.7 mm) to represent an improperly placed FH tunnel at risk of lateral cortical breach. For negative controls and salvage experimental groups, FH tunnels were drilled from anterolateral to posterolateral (lateral cortex thickness, 2.7 ± 0.9 mm). Three salvage fixation techniques were compared: suture anchor fixation, tunnel redrilling, and nitinol staple fixation. Samples (n = 5 per group) underwent uniaxial tension testing, and the ultimate tensile strength (UTS) and mode of failure were recorded. Data were analyzed using the 1-sample t test and nonparametric 1-sample Wilcoxon signed-rank test. The negative control group had a 4-fold lower mean UTS relative to the positive control group (1.49 ± 0.17 vs 6.25 ± 1.98 MPa; P < .01) and exhibited failure through the lateral cortex and tunnel. Nitinol staple fixation improved the mean UTS by >16 times compared with the negative control group (24.06 ± 6.49 vs 1.49 ± 0.17 MPa; P < .01). Suture anchors and tunnel redrilling exhibited similar UTS and mode of failure to those of negative controls. Reinforcement of a thinned lateral FH cortex with a single nitinol staple improved graft fixation strength in a sawbones model. A lateralized FH tunnel can be a common intraoperative pitfall during PLC reconstruction. Salvage of a thinned lateral FH cortex with a single nitinol staple may reduce the risk of cortical breach and graft failure.

Knee Multiligament Reconstruction: ACL / PCL / MCL

Background: Multiligament knee injury (MLKI) is a rare, complex injury that requires surgical intervention. However, there is a lack of consensus regarding optimal timing, staging, and graft choice for ligament reconstruction. Indications: Delayed, single-stage reconstruction offers the advantage of attaining improved preoperative range of motion and potential healing of extra-articular ligaments and may be necessary in the setting of multitrauma. Technique Description: A hamstring graft was harvested and diagnostic arthroscopy performed. Three posterior portals were made for posterior cruciate ligament (PCL) reconstruction. Femoral and tibial pins were placed for both PCL and anterior cruciate ligament (ACL) tunnels, positions confirmed with fluoroscopy, and tunnels drilled over the pins. The Achilles allograft was shuttled through the femoral and tibial PCL tunnels in anterograde fashion and fixed with a metal interference screw on the femoral side. The hamstring autograft was passed through the ACL tunnels and suspended on the femoral side. Tibial fixation of both grafts was achieved with biocomposite interference. Medial collateral ligament reconstruction was performed through the medial incision from hamstring harvesting. The semitendinosis allograft was passed and fixed with screws and spiked washers. Fluoroscopy confirmed that screw trajectory did not interfere with the ACL or PCL tunnels. Results: Bagherifard et al reported a study of 41 consecutive patients with MLKI who underwent single-stage reconstruction with autograft and/or allograft. Mean postoperative Lysholm and International Knee Documentation Committee (IKDC) scores were 86.9 and 70, respectively, and only 7 patients experienced restricted range of motion. Billieres et al reported a study of 23 patients with MLKIs who underwent single-stage reconstruction with allograft only. Mean postoperative Lysholm and IKDC scores were 77.3 and 67.2, respectively, and 19 patients returned to sport. Goyal et al reported a study of 27 patients with MLKI who underwent single-stage reconstruction greater than 6 weeks after injury. At 2 years, there were significant improvements in Visual Analog Scale, IKDC, and Lysholm scores, and no patients had residual laxity of the knee joint. Discussion/Conclusion: Single-stage reconstruction of MLKIs is an effective intervention that has been supported in literature; however, further studies are necessary to determine optimal surgical timing and graft type. The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Can a bioactive interbody device reduce the cost burden of achieving lateral lumbar fusion?

Intervertebral devices are increasingly utilized for fusion in the lumbar spine, along with a variety of bone graft materials. These various grafting materials often have substantial cost burdens for the surgical procedure, although they are necessary to overcome the limitations in healing capacity for many traditional interbody devices. The use of bioactive interbody fusion devices, which have demonstrable stimulatory capacity for the surrounding osteoblasts and osteoprogenitor cells and allow for osseointegration, may reduce this heavy reliance on osteobiologics for achieving interbody fusion. The objective of this study was to evaluate the rate of successful interbody fusion with a bioactive lateral lumbar interbody titanium implant with limited volume and low-cost graft material. The authors conducted a retrospective study (May 2017 to October 2018) of consecutively performed lateral lumbar interbody fusions with a bioactive 3D-printed porous titanium interbody device. Each interbody device was filled with 2-3 cm3/cage of a commercially available ceramic bone extender (β-tricalcium phosphate-hydroxyapatite) and combined with posterior pedicle screw fixation. No other biological agents or grafts were utilized. Demographic, clinical, and radiographic variables were captured. Fusion success was the primary endpoint of the study, with graft subsidence, fixation failure, and patient-reported outcomes (Oswestry Disability Index [ODI] and visual analog scale [VAS]-back and -leg pain scores) collected as secondary endpoints. The authors utilized a CT-based fusion classification system that accounted for both intervertebral through-growth (bone bridging) and ingrowth (integration of bone at the endplate-implant interface). In total, 136 lumbar levels were treated in 90 patients. The mean age was 69 years, and 63% of the included patients were female. Half (50.0%) had undergone previous spinal surgery, and a third (33.7%) had undergone prior lumbar fusion. A third (33.7%) were treated at multiple levels (mean levels per patient 1.51). One year after surgery, the mean improvements in patient-reported outcomes (vs preoperative scores) were -17.8 for ODI (p < 0.0001), -3.1 for VAS-back pain (p < 0.0001), and -2.9 for VAS-leg pain (p < 0.0001). Bone bridging and/or appositional integrity was achieved in 99.3% of patients, including 97.8% who had complete bone bridging. No fixation loosening or implant failure was observed at any segment. Low-grade graft subsidence (Marchi grade ≤ I) occurred in 3 levels (2.2%), and intraoperative endplate violation occurred twice (1.5%). High-grade subsidence was not found. No implant failure or revision surgery for pseudarthrosis/subsidence was necessary. The use of bioactive titanium interbody devices with a large surface footprint appears to result in a very high rate of effective fusion, despite the use of a small volume of low-cost biological material. This potential change in the osteobiologics required to achieve high fusion rates may have a substantially beneficial impact on the economic burden inherent to spinal fusion.