Bioabsorbable Screws Research Articles

Comparable Tibial Tunnel Widening despite Compound Differences of Bioabsorbable Interference Screws in Anterior Cruciate Ligament Reconstruction: a Retrospective Study

Comparable Tibial Tunnel Widening despite Compound Differences of Bioabsorbable Interference Screws in Anterior Cruciate Ligament Reconstruction: a Retrospective Study

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.

Tibial graft fixation in anterior cruciate ligament reconstruction: multiple tibial tunnel technique (collateral tunnel technique).

This study aimed to compare the outcomes of patients with an anterior cruciate ligament (ACL) rupture who underwent tibial fixation using the multiple tibial tunnel fixation (MTTF) and standard tibial fixation methods. This retrospective study was conducted between January 1, 2020, and August 1, 2021. MTTT was applied to 43 patients diagnosed with ACL rupture. Of the 43 patients who met the study criteria, 38 were classified as Group 1. In the clinic where the study was conducted, 40 of 57 patients who underwent standard ACL reconstruction by opening a single tibial tunnel were assigned to Group 2. The Endobutton technique was used for fixation of the graft to the femur in both groups. Bioabsorbable and postfix screws were used for the tibial fixation of the patients in Group 2. For patients in Group 1, a bioabsorbable screw, a postfix screw, and an additional MTTT fixation were performed for tibial fixation. Lachman, anterior drawer, Pivot-Shift test results, Lysholm and IKDC knee evaluation scores of the patients in both groups were compared. In this study, there was no significant difference between the groups for the anterior drawer, Lachman, and Pivot-Shift test results at the final control (p > 0.05). There was a significant difference between the two groups for the Lysholm and IKDC scores at the final controls (p < 0.05). There was a significant difference in the Lysholm and IKDC scores between the groups (p < 0.05). In conclusion, ACL reconstruction was performed using the MTTF technique in this study. Due to the additional fixation, it was observed that the patients had a more successful knee function after the surgery.

Treatment of Moderate to Severe Hallux Valgus without Osteotomy or Arthrodesis

Category: Bunion Introduction/Purpose: Hallux valgus is a multi-planar deformity that has historically required osteotomies to correct a soft tissue deficiency. We present a novel technique for the treatment of moderate to severe hallux valgus and subsequent radiographic results of a method to correct the intermetatarsal abnormality without utilizing osteotomies or arthrodesis. Methods: One hundred and thirty-six patients undergoing primary metatarsal re-alignment with modified McBride for moderate to severe hallux valgus were included. After each patient underwent standard distal soft tissue procedure via modified McBride bunionectomy, the first metatarsal was manually reduced and brought parallel to the second. It was then held temporarily with a K-wire and position assessed to ensure the first and second metatarsal heads are in the same transverse plane to prevent relative plantar or dorsiflexion of the first ray. A bioabsorbable screw was then placed obliquely from the base of the first into the bases of the second and third metatarsals. Patients were assessed pre-operatively, at 2 weeks, 6 weeks, and 3 months for early clinical outcome, complications, and radiographic evaluation. The hallux valgus angle (HVA) and intermetatarsal angle (IMA) were recorded and used to monitor any progression or change over time. Results: This procedure allows for significant correction of moderate and severe hallux valgus deformities with little radiographic evidence of loss of reduction in early clinical follow-up. One and two-year follow-up was included for patients where available. Pre-operative assessment of HVA and IMA were 32.3° (95% CI: 31.1-33.5) and 14.8° (95% CI: 14.2-15.3), respectively. Post- operative HVA was significantly improved at 2 weeks (10.4°), 6 weeks (11.1°), and 3 months (12.1°). IMA was improved at 2 weeks (6.0°), 6 weeks (6.8°) and 3 months (7.8°). One (48 patients) and two-year follow-up (20 patients) show maintenance of correction of both HVA (1yr: 12.7°, 2yr: 10.8°) and IMA (1yr: 7.9°, 2yr: 8.0°). Complications were few including iatrogenic hallux varus (2/136, 1.4%), peri-implant fractures at the second metatarsal base (3/136, 2.2%), and valgus relapse, which was the only complication requiring re-operation (3/136, 2.2%). Conclusion: When combined with modified McBride bunionectomy, this proximal metatarsal realignment procedure provides a simple and effective method for the treatment of moderate to severe hallux valgus deformities. Additionally, there is minimal radiographic evidence of loss of reduction over time. This procedure is simple to perform, easy to learn, and does not 'burn any bridges' with regards to future surgery.

Current trends in anterior cruciate ligament surgery. A worldwide benchmark study

ObjectivesTo benchmark current trends on anterior cruciate ligament reconstruction (ACLR) surgery. MethodsThe largest worldwide ACLR survey to date was performed during May 2020, targeted to reach representation of all continents. It was submitted electronically to all International Society of Arthroscopy, Knee Surgery and Orthopaedic Sports surgeons (n = 3,026), asking those who perform ACLR to respond. ResultsWith a final sample size of 2,107, the overall response rate was 69.6%. Median years of practice as orthopaedic surgeon was 15 (range 1–52) and 49.6% of all respondents were defined as high-volume surgeons (>50 ACLR annually). Hamstrings tendon autograft was the preferred graft for primary ACLR (80.3%) and the medial portal femoral drilling was the most frequently used technique (78.5%). Cortical buttons (82.7%) and bioabsorbable screws (62.7%) were the preferred fixation methods for hamstring tendon autograft ACLR in femur and tibia, respectively. Metallic screws (45.2%) were the preferred fixation methods for bone patellar tendon bone autograft in femur and tibia. Most of the respondents routinely used pre-tensioning techniques for their graft preparation (63.8%), but less than half of surgeons preferred antibiotic soaking of the grafts (45.3%). The preferred knee position for graft fixation was 10–30° of knee flexion and neutral rotation (57.0%). The addition of anterolateral augmentation (or extra-articular tenodesis) was infrequent in primary and isolated ACLR (10.0%), but a statistically significant raise was seen for revision surgeries (20.0%). Most used brace in the initial postoperative rehabilitation (54.9%) and the time to allow patients to fully resume sports was at an average of 8.9 ± 2.0 months. Treatment algorithm of paediatric ACL injuries exhibited a low consensus among the respondents. ConclusionThis worldwide survey benchmarks the current trends in ACL reconstruction, achieving the largest participation of surgeons to date. Among the great variety of options available for ACL reconstructions, surgeons’ preferences showed some differences according to their location and expertise. Reporting trends in practice, and not only the evidence, is important to medical education and providing patients the safest care possible.This is a Level V, expert opinion study.

Novel Posterior Anchoring Method Associated With Medial Meniscus Posterior Root Repair

Introduction: Transtibial pullout repair is the gold standard surgical treatment for medial meniscus (MM) posterior root tear. However, posteromedial extrusion of the MM during knee flexion may remain a problem postoperatively. Materials and Methods: We used a novel posterior anchoring technique to help reduce posteromedial extrusion, applying two cinch sutures (TCSs) to the MM posterior horn and creating a bone tunnel at the center of the posterior root attachment to pullout the suture. Another bone tunnel was created at the posterior corner of the medial tibial plateau in the externally rotated knee flexion. The first anchor of an all-inside meniscal repair device was inserted through the inferior surface of the MM posterior horn with tensioning TCS and the second anchor into the bone tunnel. Tibial fixation of pullout sutures was performed using a bioabsorbable screw in 30 degrees knee flexion. Conclusions: Our posterior anchoring method, combined with conventional pullout repair with TCS, helped reduce posteromedial extrusion in patients with a MM posterior root tear.

Outcomes Following Bone-patellar Tendon-Bone Anterior Cruciate Ligament Reconstruction In Patients &lt;30 Years: Allograft Vs. Autograft

PURPOSE: The purpose of this study was to investigate differences in failure rates and functional outcomes between patients <30 years of age that underwent allo- or autograft Bone-Patellar Tendon-Bone (BPTB) ACLR. METHODS: All patients aged 16-30 years who underwent a BPTB allo- or autograft ACLR with bioabsorbable interference screws by a single surgeon (1995-2019) were included. Exclusion criteria were follow-up <2 years, osteochondral drilling, revision ACLR, and multi-ligamentous injuries. The allograft was always <5 years than patient age and not terminally irradiated. Meniscal repairs were completed as necessary. All patients completed a decelerated, conservative rehab program with required bracing for 3 months and return to pivoting sports >6 months. An independent physical exam including knee ROM and stability testing, (manual max KT-1000, Lachman, pivot shift) was performed. Patients completed Lysholm, IKDC, Tegner and pain Visual Analogue Score (VAS) to assess clinical outcomes. Failure was defined as positive Lachman or pivot shift test or MRI evidence of re-tear. RESULTS: 13 patients with BPTB allograft (5 male/8 female; 24.3 ± 4.0 years) and 35 patients with BPTB autograft (28 males/7 females; 22.3 ± 4.2 years) ACLR were included (p = 0.136). Average follow-up was 11.7 ± 3.9 years in the allograft group and 13.9 ± 5.9 years in the autograft group (p = 0.685). There were no significant differences in functional outcomes between groups (Lysholm: p = 0.226; IKDC: p = 0.107; Tegner: p = 0.610). There was no significant difference in laxity between groups (KT-1000 30 lbs: p = 0.131; manual maximum: p = 0.416; side to-side difference 30 lbs: p = 0.310; side-to-side difference manual max: p = 0.472). All patients returned to preoperative sports (Tegner score ≥ 5). Overall failure rate was 1.8% (1/48) with 1 failure in the autograft group (p = 0.548). CONCLUSION: In this cohort of young patients, no difference in failure rate was seen between allograft and autograft. At a mean of >10-year follow-up, laxity and all patient reported outcomes were not different between the groups. Careful selection of an allograft for use in ACLR and a decelerated rehabilitation program can be a good alternative in young patients >30 years to return to preoperative sports with no evidence of increased failure rates in this cohort.

Comparative Results of Anterior Cruciate Ligament Reconstruction with Full Tibial Tunnel: Quadrupled Semitendinosus Suspensory Femoral and Tibial Fixation versus Quadrupled Semitendinosus and Gracilis Suspensory Femoral and Tibial Screw and Staple Fixation.

This study compared the clinical outcomes of patients treated with described "modified all-inside" anterior cruciate ligament reconstruction (ACLR) technique with those of patients treated with suspensory femoral fixation and a bioabsorbable tibial interference screw with the ACLR technique. From 2017 to 2019, 98 patients who underwent ACLR surgery by two surgeons using either of the techniques were included in this study. Patients in group 1 were treated with the "modified all-inside" ACLR technique. In this technique, only the semitendinosus tendon was harvested as a four-strand graft and fixed to the tibia and femur with suspensory buttons. Patients in group 2 were treated with suspensory femoral fixation and a bioabsorbable tibial interference screw ACL reconstruction technique. Patients' functional outcomes were evaluated by the Lysholm score, Tegner activity scale, and International Knee Documentation Committee (IKDC) subjective score. Postoperative knee stability of the patients was evaluated using the Lachman test and the pivot-shift test. The mean ages of the patients were 31.1 (16-55) and 28.7 (18-48) years in groups 1 and 2, respectively. The average follow-up durations were 26 (20-30) and 25.9 (22-30) months for both groups. There was no significant difference between the preoperative and postoperative Lysholm's score, Tegner's activity score, and IKDC subjective score in groups 1 and 2. There were no major complications or reruptures in either group. ACLR incorporating the "modified all-inside" ACLR technique obtained significant clinical outcomes compared to ACLR with a suspensory femoral fixation and a bioabsorbable tibial interference screw.

Clinical and Radiologic Outcome of First Metatarsophalangeal Joint Arthrodesis Using a Human Allogeneic Cortical Bone Screw.

Background:Different fixation techniques are established for first metatarsophalangeal joint (MTPJ) arthrodesis, including compression screws, plates, Kirschner wires, metal- and bioabsorbable screws as well as staples. The purpose of this study was to investigate and present first clinical and radiologic results using a novel human, allogeneic cortical bone screw for arthrodesis of the first MTPJ.Methods:Arthrodesis of the first MTPJ was performed in 31 patients with hallux rigidus. Percentage union and time to union were the first outcomes; visual analog scale for pain, hallux valgus angle (HVA), intermetatarsal angle, and American Orthopaedic Foot & Ankle Society (AOFAS) hallux score were secondary outcomes.Results:Median time to union was 89 days, and union was observed in all patients. There were 4 complications (2 osteolysis margin, 1 cystic brightening, and 1 severe swelling at the first follow-up) all of that resolved at last follow-up. Pain significantly decreased from visual analog scale 8.0 to 0.2 points (P < .0001). The HVA decreased from 30.4 to 10.2 degrees in the patient group with deformities. The total AOFAS score increased significantly from 48 to 87 (P < .0001).Conclusion:Primary and revision arthrodesis of hallux rigidus with the human, allogeneic cortical bone screw reveals satisfying results similar to clinical and radiologic outcomes of other surgical techniques. Within 1 year, the human, allogeneic cortical bone screw is fully remodeled to host bone.Level of Evidence:Level IV, retrospective case series without control group.

Minimally Invasive Mid-Substance Achilles Tendon Repair Using the Percutaneous Achilles Repair System (PARS).

Minimally Invasive Mid-Substance Achilles Tendon Repair Using the Percutaneous Achilles Repair System (PARS).

ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION WITH HAMSTRING AUTOGRAFT USING BIOABSORBABLE VERSUS TITANIUM INTERFERENCE SCREW IN TIBIAL TUNNEL IN GOVERNMENT HOSPITAL OF WEST NEPAL

Background: Arthroscopic anterior cruciate ligament reconstruction can be performed both with titanium and bioabsorbable interference screws. The purpose of this study was to com­pare functional outcomes after reconstruction using these different implants. Methods: This was a retrospective study. Patients who underwent ACL reconstruction with ham­string autograft at Bheri hospital over the designed period were observed. Each group (titanium and bioabsorbable screws) consisting of 20 patients were compared using Lyshlom knee scores at 3, 6 and 12 months postoperatively. Statistical analysis was done using SPSS version 24. Chi square test was applied for comparing functional outcomes. Confidence interval of 95%, p value less than 0.05 was taken as significant. Results: Mean Lyshlom scores at 3, 6 and 12 months were 61.70, 69.60 &amp; 85.90 for titanium group and 62.65, 70.95 &amp; 84.65 for bioabsorbable screw group. The differences were not statistically significant. Conclusions: Functional outcomes at each follow up was equivalent among patients using either titanium or bioabsorbable screws.

Radiographic features of magnesium-based bioabsorbable screw resorption in paediatric fractures.

Resorption of magnesium-based alloy bioabsorbable screws produces hydrogen gas, which can be mistaken as a sign of infection and may affect the physis or fixed bone fragment. We evaluated the temporal and spatial occurrence of gas and the occurrence of a breakage of the fixed bone fragment or screw following magnesium screw fixation. Radiographs of paediatric patients treated with magnesium screws were retrospectively reviewed. Temporal occurrence and distribution of gas in the bone, the physis and soft tissues, breakage of the screw or fixed bone fragment and joint effusion were assessed. One hundred and three radiographs in 35 paediatric patients were reviewed (mean age: 10.6years). Follow-up ranged from 1 to 730days. Gas in the bone increases up to week 5, remains constant up to week 16 and then decreases. Gas in soft tissues, intra-articular gas and joint effusions gradually reduce over time. In 1/23 (4.3%) patients with an open physis, gas intrusion into the physis occurred. Breakage of the bone fragment fixated by the screw was observed in 4/35 (11.4%) patients within the first 6weeks. Screw breakage was observed in 16/35 (45.7%) patients, with a median time to first detection of 300days. Gas bubbles in bone and soft tissue are normal findings in the context of screw resorption and should not be confused with soft-tissue infection or osteomyelitis. Gas is rarely visible in the physis. Breakage of the fixed bone fragment and/or screw can occur.

Anterior Cruciate Ligament Reconstruction with 4-Strand Hamstring Tendon Construct May be Biomechanically Superior to 5-Strand Hamstring Tendon Construct When Using Femoral Suspensory Fixation

PurposeTo compare stiffness, strain, and load to failure of 4- versus 5-strand hamstring anterior cruciate ligament reconstruction human tendon allografts with femoral suspensory and tibial interference screw fixationMethodsAllograft hamstring tendons were used to create 10 four-strand (4S) and 10 five-strand (5S) grafts. Grafts were fixed to a uniaxial electromechanical load system via a femoral cortical suspensory button and a bioabsorbable interference screw in bone analogue. Grafts were cycled from 100 Newtons (N) to 250 N for 1,000 repetitions at 0.5 hertz before load to failure testing. Cyclic displacement was defined as the difference in graft length from the first 20 to 30 cycles compared with the last 10 cycles. Trials were recorded on a high-definition camera to allow for digital image correlation analysis.ResultsCyclic displacement more than 1,000 cycles was significantly lower in the 4S compared with the 5S group (0.87 vs 1.11 mm, P = .037). Digital image correlation analysis confirmed that the fifth strand elongated more than the other 4 strands in the 5S constructs (6.1% vs 3.9%, P = .032). Load to failure was greater in the 4S compared with the 5S group but not statistically significant (762 vs 707 N, P = .35). Stiffness was similar between constructs (138.5 vs 138.3 N/mm, P = .96)ConclusionsCompared with cyclically loaded 4S hamstring grafts, the 5S grafts had significantly increased displacement over time in a model of femoral suspensory and tibial interference screw fixation.Clinical RelevanceAnterior cruciate ligament reconstruction with hamstring tendon autograft is a commonly performed surgery with excellent outcomes. It has been shown that graft diameter influences these outcomes. As surgeons use larger grafts, it is important to investigate how these constructs may affect the outcomes of surgery.

Biomechanical comparison between bioabsorbable and medical titanium screws in distal chevron osteotomy of first metatarsal in hallux valgus treatment

Polylactic acid (PLA) composite materials have been used for manufacturing surgical internal fixations owing to their satisfactory mechanical strength and absorbability. This, in turn, reduces the pain and risks associated with the secondary operation on patients. Although the mechanical properties of bioabsorbable materials have been considerably enhanced via modifications and optimization, the strength and stiffness of these materials are considerably inferior to those of metals. Therefore, whether PLA fixation can satisfy the required mechanical properties has been a consistent subject of interest in clinical practice. In this study, the mechanical properties of PLA bioabsorbable (Changchun SinoBiomaterials Co., Ltd., China) and titanium hollow screws (Shanghai Carefix Medical Instrument Co., Ltd., China) were compared in hallux valgus surgery with chevron osteotomy. Three-dimensionally printed osteotomy guides were used for cutting the artificial first metatarsal model (SKU3422, Sawbones) to reduce the errors due to the variations in individual bone densities and osteotomy angles; the cut parts were subsequently fixed with the PLA and titanium alloy screws. A digital image correlation system was used to obtain the full-field strain of the specimen to evaluate the mechanical behaviors under static and fatigue loads. The experimental results demonstrated that, by designing a reasonable osteotomy angle, the compressive strength of the specimen with PLA screws under chevron osteotomy can be as high as that of the specimen with titanium screws. Moreover, their stiffness can reach up to 60%–90% that of titanium screws. After 240,000 cycles of compression, the PLA screws maintained their strength and stiffness. These bioabsorbable fixtures can effectively prevent stress shielding under a suitable osteotomy. Hence, as an optimal substitute for metal fixtures, an increase in clinical applications to surgery is anticipated, along with progressive in-depth research on the biomechanical properties of bioabsorbable materials.

The effect of additional staple in the tibial fixation of anterior cruciate ligament reconstruction: a biomechanical study in sheep tibia

Objectives: The aim of this study was to evaluate the necessity of staple use and the importance of screw diameter in the anterior cruciate ligament (ACL) reconstruction. Methods: Twenty-eight sheep hind legs were divided into four groups in terms of tibial side fixation type as 7 mm bioabsorbable screw (Group 1), 7 mm bioabsorbable screw and staple (Group 2), 8 mm screw (Group 3), and 8 mm screw and staple (Group 4). The maximum force causing insufficiency in the graft, and the fixation strength between the groups were recorded. The results were compared among the groups. Results: As a result of the statistical analysis regarding the necessity of using staple, group 2, with 7 mm screws and staple, was found to be significantly more resistant than group 1 (p = 0.018). In consequence of the biostatistics study, staple use was found not to create a statistically significant difference between group 3 in which an 8 mm bioabsorbable screw was used and group 4 (p = 0.805). In the statistical study to understand the significance of screw diameter, the samples of group 1 and group 3, in which no staple was used, were compared. It was found that group 3 samples with 8 mm screws had higher strength than those with 7 mm screws (p = 0.011). Between group 2 and group 4 in which a staple was used, despite the increase in screw diameter, the value of maximum strength had no remarkable difference statistically (p = 1.00). Conclusions: Fixation strength is higher when fixation was done with a screw 1 mm larger than tibial tunnel diameter. However, using either a screw with 1 mm wider than tibial tunnel diameter and the screw in the same diameter with the tibial tunnel and additional staple have similar fixation strength on the tibial side. Therefore, we conclude that screw width is more important in maintaining stability of the graft fixation.

Comparaison clinique et radiologique des vis d’interférence biorésorbables en verre bioactif versus en acide poly-L-lactique/hydroxyapatite pour la fixation de greffe tibiale dans la reconstruction du ligament croisé antérieur

BackgroundLigament reconstruction is still the main treatment modality for patients with a complete ligament rupture. The semitendinosus tendon, alone quadrupled or double folded and combined with the gracilis tendon is still the most frequently used autologous graft for a reconstructive procedure. Absorbable interference screw usage has gained popularity in the past decade because they create less artifacts during MR imaging and tend to osteointegrate over the years, arguably leading to a more anatomic fixation. The purpose of this study was to compare the 5-year radiological and clinical results of two different tibial graft fixation screws. HypothesisWe hypothesized that bioabsorbable interference screws made of bioactive glass would lead to higher rates of osteointegration, better overall clinical results, less foreign body reaction rates and less tibial tunnel widening when compared to the poly-L-lactic acid/hydroxyapatite (PLLA-HA) screws. Patients and methodsFifty-one patients treated with an anatomic single bundle ACL reconstruction between June 2015 and July 2016 at our institution were included in the study. The tibial graft was fixed with a bioactive glass screw in 24, and with a PLLA-HA in 27 patients. Tibial tunnel widening, foreign body reaction, osteointegration and resorption rates were evaluated and compared on a magnetic resonance scan at a minimum of 5 year postoperatively. Overall clinical results and side-to-side difference on KT-1000 were also analyzed in-between groups. ResultsTibial tunnel widening was similar for both groups. Foreign body reaction, while not statistically significant, was less aggressive when bioactive glass screws were used. Osteointegration and resorption rates of the bioactive glass screws were significantly higher than the PLLA-HA group (p=0.000). While all patients showed an overall improvement on postoperative scores (p=0.000), patients with a bioactive glass interference screw had statistically higher translational stability with KT-1000, compared to the poly-L-lactic acid/hydroxyapatite group (p=0.001). DiscussionAt a minimum of 5years, compared to conventional PLLA-HA interference screws, 45S5 bioactive glass screw provide higher resorption rates, are more highly biodegradable and provide overall good clinical results. Level of evidenceIII.

Mechanical and biological behaviour of additive manufactured biomimetic biodegradable orthopaedic cortical screws

PurposeThe complications caused by metallic orthopaedic bone screws like stress-shielding effect, screw loosening, screw migration, higher density difference, painful reoperation and revision surgery for screw extraction can be overcome with the bioabsorbable bone screws. This study aims to use additive manufacturing (AM) technology to fabricate orthopaedic biodegradable cortical screws to reduce the bone-screw-related-complications.Design/methodology/approachThe fused filament fabrication technology (FFFT)-based AM technique is used to fabricate orthopaedic cortical screws. The influence of various process parameters like infill pattern, infill percentage, layer height, wall thickness and different biological solutions were observed on the compressive strength and degradation behaviour of cortical screws.FindingsThe porous lattice structures in cortical screws using the rapid prototyping technique were found to be better as porous screws can enhance bone growth and accelerate the osseointegration process with sufficient mechanical strength. The compressive strength and degradation rate of the screw is highly dependent on process parameters used during the fabrication of the screw. The compressive strength of screw is inversely proportional to the degradation rate of the cortical screw.Research limitations/implicationsThe present study is focused on cortical screws. Further different orthopaedic screws can be modified with the use of different rapid prototyping techniques.Originality/valueThe use of rapid prototyping techniques for patient-specific bone screw designs is scantly reported. This study uses FFFT-based AM technique to fabricate various infill patterns and porosity of cortical screws to enhance the design of orthopaedic cortical screws.

Clinical and radiological comparison of bioactive glass and poly-L-lactic acid/hydroxyapatite bioabsorbable interference screws for tibial graft fixation in anterior cruciate ligament reconstruction

BackgroundLigament reconstruction is still the main treatment modality for patients with a complete ligament rupture. The semitendinosus tendon, alone quadrupled or double folded and combined with the gracilis tendon, is still the most frequently used autologous graft for a reconstructive procedure. Absorbable interference screw usage has gained popularity in the past decade because they create less artifacts during MR imaging and tend to osteointegrate over the years, arguably leading to a more anatomic fixation. The purpose of this study was to compare the 5-year radiological and clinical results of two different tibial graft fixation screws. HypothesisWe hypothesized that bioabsorbable interference screws made of bioactive glass would lead to higher rates of osteointegration, better overall clinical results, less foreign body reaction rates and less tibial tunnel widening when compared to the poly-L-lactic acid/hydroxyapatite (PLLA-HA) screws. Patients and methodsFifty-one patients treated with an anatomic single bundle ACL reconstruction between June 2015 and July 2016 at our institution were included in the study. The tibial graft was fixed with a bioactive glass screw in 24, and with a PLLA-HA in 27 patients. Tibial tunnel widening, foreign body reaction, osteointegration and resorption rates were evaluated and compared on a magnetic resonance scan at a minimum of 5 year postoperatively. Overall clinical results and side-to-side difference on KT-1000 were also analyzed in-between groups. ResultsTibial tunnel widening was similar for both groups. Foreign body reaction, while not statistically significant, was less aggressive when bioactive glass screws were used. Osteointegration and resorption rates of the bioactive glass screws were significantly higher than the PLLA-HA group (p=0.000). While all patients showed an overall improvement on postoperative scores (p=0.000), patients with a bioactive glass interference screw had statistically higher translational stability with KT-1000, compared to the poly-L-lactic acid/hydroxyapatite group (p=0.001). DiscussionAt a minimum of 5 years, compared to conventional PLLA-HA interference screws, 45S5 bioactive glass screw provide higher resorption rates, are more highly biodegradable and provide overall good clinical results. Level of evidenceIII.

CORRELATION OF FUNCTIONAL STATUS OF ARTHROSCOPIC ACL RECONSTRUCTION FOR PREVENTION OF TITANIUM INTERFERENCE SCREW

INTRODUCTION: Due to an increase in traffic accidents and more common people participating in sports-related activities, knee injuries are more frequent today. The knee's anterior cruciate ligament is the ligament that gets injured the most frequently. The principal stabiliser that prevents the anterior translation of the tibia over the femur is the anterior cruciate ligament, which plays a pivotal role in the stability and function of the knee joint. The gold standard for treating these injuries is arthroscopic anterior cruciate ligament reconstruction. Methods: This study is a retrospective and prospective analysis of 60 patients who underwent arthroscopic reconstruction of the anterior cruciate ligament using a quadrupled hamstring graft with an endobutton as the femoral fixation device and a titanium interference screw (no=30) or a bioabsorbable interference screw (no=30) as the tibial fixation device. Results: This study is a retrospective and prospective analysis of 60 patients who underwent arthroscopic reconstruction of the anterior cruciate ligament using a quadrupled hamstring graft with an endobutton as the femoral fixation device and a titanium interference screw (no=30) or a bioabsorbable interference screw (no=30) as the tibial fixation device. CONCLUSION: Clinical outcomes for interference screws made of titanium and bioabsorbable material are statistically comparable. The two screws' complication rates were comparable as well. This comparison analysis's findings are consistent with the claim that titanium screws and bioabsorbable screws both produce comparable results when used for ACL restoration.

Evaluation of the degradation of two bioabsorbable interference screws: an in-vivo study in sheep.

ABSTRACTPurpose:To evaluate in-vivo degradation of two bioabsorbable interference screws.Methods:Twenty-two crossbred Santa Inês ewes were used. A poly-DL-lactide (PDLLA) screw (70%/30%) was inserted in the right pelvic limb, and a PDLLA screw (70%) + β-tri-calcium phosphate (β-TCP) (30%) in the left pelvic limb. Animals were euthanized at one, four, seven and a half and 18 months after surgery. Plain radiography, computed tomography (CT), microCT, and histological analysis were accomplished.Results:PDLLA screw was hypodense at all evaluation moments, but with progressive density increase along the central axis, whereas PDLLA/β-TCP was initially hyperdense and progressively lost this characteristic. No adverse reactions were observed on histological evaluation.Conclusions:The inclusion of β-TCP favors screw degradation since the PDLLA/β-TCP screws evidenced a more intense degradation process than the PDLLA screws at the last evaluation. PDLLA screws showed higher bone production, evident around the screw thread, inside the lateral perforations, and in the central canal, whereas the PDLLA/β-TCP screws presented less bone tissue at the implantation site.