In the 1960's Sir John Charnley introduced to clinical practice his low friction arthroplasty with a highly polished cemented femoral stem. The satisfactory long term results of this and other cemented stems support the use of polymethylmethacrylate (PMMA) for fixation. The constituents of PMMA remain virtually unchanged since the 1960s. However, in the last three decades, advances in the understanding of cement fixation, mixing techniques, application, pressurization, stem materials and design provided further improvements to the clinical results. The beneficial changes in cementing technique include femoral preparation to diminish interface bleeding, pulsatile lavage, reduced cement porosity by vacuum mixing, the use of a cement restrictor, pre-heating of the stem and polymer, retrograde canal filling and pressurization with a cement gun, stem centralization and stem geometries that increase the intramedullary pressure and penetration of PMMA into the cancellous structure of bone. Some other changes in cementing technique proved to be detrimental and were abandoned, such as the use of Boneloc cement that polymerised at a low temperature, and roughening and pre-coating of the stem surface. In the last two decades there has been a tendency towards an increased use of cementless
In the 1960s Sir John Charnley introduced to clinical practice his low friction arthroplasty with a highly polished cemented femoral stem. The satisfactory long term results of this and other cemented stems support the use of cement for fixation. The constituents of acrylic cement remained virtually unchanged since the 1960s. However, in the last three decades, advances in the understanding of cement fixation, mixing techniques, application, pressurization, stem materials and design provided further improvements in the clinical results. The technical changes in cementing technique that proved to be beneficial include femoral preparation to diminish interface bleeding, careful lavage, reduced cement porosity by vacuum mixing, a cement restrictor, pre-heating of the stem and polymer, retrograde canal filling and pressurization with a cement gun, stem centralization and stem geometries that increase the intramedullary pressure and intrusion into the bone of the cement. Some other changes proved to be detrimental and were abandoned, such as the use of Boneloc cement that polymerised at a low temperature, and roughening and pre-coating of stem surface. In recent years there has been a tendency towards an increased use of cementless
Transverse pin
The initial success of modern total hip arthroplasty can in large part be attributed to the reliable fixation of the femoral component with the use of acrylic bone cement. Early success with cement led to a common pathway of development in North America and the European countries. Much of the early- to mid-term research concentrated on refinement of variables related to the methodology and technique of cement fixation. Scandinavian registries were subsequently able to report on improved survivorship with better cementing technique. The net effect has been standardisation towards a small number of cemented implants with good long-term outcomes representing the majority of stems implanted in Sweden, for example. In North America, during the mid-term development of THA in the late 1980's, the term “cement disease” was coined and the cemented THA saw a precipitous decline in use, now to the point where many American orthopaedic residents are completing training never having seen a cemented THA. Modern uncemented femoral components can now claim good long-term survivorship, perhaps now comparable to cemented fixation. However, this has come at a cost with respect to the premium expense applied to the implant itself as well as lineage of failed uncemented constructs. The last several years have seen a proliferation of uncemented implants, usually at a premium cost, with no demonstrated improvement in survivorship. Osteolysis has not been solved with uncemented implants and cement disease has largely been recognised as a misnomer. Long-term outcomes of cemented
Tibial and femoral bone tunnel widening (TW) has been observed following anterior cruciate ligament (ACL) reconstruction. We developed a χ12 mm cannulated cancellous screw (Intercondylar Ligament Screw, ICLS) for
There is conjecture on the optimal timing to administer bisphosphonate therapy following operative fixation of low- trauma hip fractures. Factors include recommendations for early opportunistic commencement of osteoporosis treatment, and clinician concern regarding the effect of bisphosphonates on fracture healing. We performed a systematic review and meta-analysis to determine if early administration of bisphosphonate therapy within the first month post-operatively following proximal femur fracture fixation is associated with delay in fracture healing or rates of delayed or non-union. We included randomised controlled trials examining fracture healing and union rates in adults with proximal femoral fractures undergoing osteosynthesis fixation methods and administered bisphosphonates within one month of operation with a control group. Data was pooled in meta-analyses where possible. The Cochrane Risk of Bias Tool and the GRADE approach were used to assess validity. For the outcome of time to fracture union, meta-analysis of three studies (n= 233) found evidence for earlier average time to union for patients receiving early bisphosphonate intervention (MD = −1.06 weeks, 95% CI −2.01 – −0.12, I2= 8%). There was no evidence from two included studies comprising 718 patients of any difference in rates of delayed union (RR 0.61, 95% CI 0.25–1.46). Meta-analyses did not demonstrate a difference in outcomes of mortality, function, or pain. We provide low-level evidence that there is no reduction in time to healing or delay in bony union for patients receiving bisphosphonates within one month of proximal femur fixation.
The number of cemented femoral stems implanted in the United States continues to slowly decrease over time. Approximately 10% of all femoral components implanted today are cemented, and the majority are in patients undergoing hip arthroplasty for femoral neck fractures. The European experience is quite different. In the UK, cemented femoral stems account for approximately 50% of all implants, while in the Swedish registry, cemented stems still account for the majority of implanted femoral components. Recent data demonstrating some limitations of uncemented fixation in the elderly for primary THA, may suggest that a cemented femoral component may be an attractive alternative in such a group. Two general philosophies exist with regards to the cemented femoral stem: Taper slip and Composite Beam. There are flagship implants representing both philosophies and select designs have shown excellent results past 30 years. A good femoral component design and cementing technique, however, is crucial for long-term clinical success. The author's personal preference is that of a “taper slip” design. The cemented Exeter stem has shown excellent results past 30 years with rare cases of loosening. The characteristic behavior of such a stem is to allow slight subsidence of the stem within the cement mantle through the process of cement creep. One or two millimeters of subsidence in the long-term have been observed with no detrimental clinical consequences. There have been ample results in the literature showing the excellent results at mid- and long-term in all patient groups. The author's current indication for a cemented stem include the elderly with no clear and definitive cutoff for age, most likely in females, THA for femoral neck fracture, small femoral canals such as those patients with DDH, and occasionally in patients with history of previous hip infection. Modern and impeccable cement technique is paramount for durable cemented fixation. It is important to remember that the goal is interdigitation of the cement with cancellous bone, so preparing the femur should not remove cancellous bone. Modern technique includes distal plugging of the femoral canal, pulsatile lavage, drying of the femoral canal with epinephrine or hydrogen peroxide, retrograde fill of the femoral canal with cement with appropriate suction and pressurization of the femoral cement into the canal prior to implantation of the femoral component. The dreaded “cement implantation syndrome” leading to sudden death can be avoided by appropriate fluid resuscitation prior to implanting the femoral component. This is an extremely rare occurrence today with reported mortality for the Exeter stem of 1 in 10,000. A cemented femoral component has been shown to be clinically successful at long term. Unfortunately, the art of cementing a femoral component has been lost and is rarely performed in the US. The number of cemented stems, unfortunately, may continue to go down as it is uncommonly taught in residency and fellowship, however, it might find a resurgence as the limits of uncemented fixation in the elderly are encountered. National joint registers support the use of cemented femoral components, and actually demonstrate higher survivorship at short term when compared to all other uncemented femoral components. A cemented femoral component should be in the hip surgeons armamentarium when treating patients undergoing primary and revision THA.
The number of cemented femoral stems implanted in the United States continues to slowly decrease over time. Approximately 10% of all femoral components implanted today are cemented, and the majority are in patients undergoing hip arthroplasty for femoral neck fractures. The European experience is quite different, in the UK, cemented femoral stems account for approximately 50% of all implants, while in the Swedish registry, cemented stems still account for the majority of implanted femoral components. Recent data demonstrating some limitations of uncemented fixation in the elderly for primary THA, may suggest that a cemented femoral component may be an attractive alternative in such a group. Two general philosophies exist with regards to the cemented femoral stem: Taper slip and Composite Beam. There are flagship implants representing both philosophies and select designs have shown excellent results past 30 years. A good femoral component design and cementing technique, however, is crucial for long-term clinical success. The authors' personal preference is that of a “taper slip” design. The cemented Exeter stem has shown excellent results past 30 years with rare cases of loosening. The characteristic behavior of such a stem is to allow slight subsidence of the stem within the cement mantle through the process of cement creep. One or two millimeters of subsidence in the long-term have been observed with no detrimental clinical consequences. There have been ample results in the literature showing the excellent results at mid- and long-term in all patient groups. The authors' current indications for a cemented stem include the elderly with no clear and definitive cutoff for age, most likely in females, THA for femoral neck fracture, small femoral canals such as those patients with DDH, and occasionally in patients with history of previous hip infection. Modern and impeccable cement technique is paramount for durable cemented fixation. It is important to remember that the goal is interdigitation of the cement with cancellous bone, so preparing the femur should not remove cancellous bone. Modern technique includes distal plugging of the femoral canal, pulsatile lavage, drying of the femoral canal with epinephrine or hydrogen peroxide, retrograde fill of the femoral canal with cement with appropriate suction and pressurization of the femoral cement into the canal prior to implantation of the femoral component. The dreaded “cement implantation syndrome” leading to sudden death can be avoided by appropriate fluid resuscitation prior to implanting the femoral component. This is a extremely rare occurrence today with reported mortality for the Exeter stem of 1 in 10,000. A cemented femoral component has been shown to be clinically successful at long term. Unfortunately, the art of cementing a femoral component has been lost and is rarely performed in the US. The number of cemented stems unfortunately may continue to go down as it is uncommonly taught in residency and fellowship, however it might find a resurgence as the limits of uncemented fixation in the elderly are encountered. National joint registers support the use of cemented femoral components, and actually demonstrate higher survivorship at short term when compared to all other uncemented femoral components. A cemented femoral component should be in the hip surgeons' armamentarium when treating patients undergoing primary and revision THA.
A large body of the orthopaedic literature clearly indicates that the cement mantle surrounding the femoral component of a cemented total hip arthroplasty should be at least 2 mm thick. In the early 1970s, another concept was introduced and is still in use in France consisting of implanting a canal filling femoral component line-to-line associated with a thin cement mantle. This principle has been named the “French paradox”. An explanation to this phenomenon has been provided by in-vitro studies demonstrating that a thin cement mantle in conjunction with a canal filling stem was supported mainly by cortical bone and was subjected to low stresses. We carried out a study to evaluate the in-vivo migration patterns of 164 primary consecutive Charnley-Kerboull total hip replacements. All prosthesis in the current series combined an all-polyethylene socket and a 22.2 mm stainless steel femoral head. The monobloc double tapered (5.9 degrees) femoral component was made of 316L stainless steel with a highly polished surface (Ra = 0.04 μm), a quadrangular section, and a neck-stem angle of 130 degrees. The stem was available in six sizes with a stem length (shoulder to tip) ranging from 110 mm to 160 mm, and a neck length ranging from 24 mm to 56 mm. For each size, the femoral component was available in two to four different diameters to adapt the implant to the medullary canal. Hence the whole range comprised a total of 18 standard femoral components. The femoral preparation included removal of diaphyseal cancellous bone to obtain primary rotational and varus/valgus stability of the stem prior to the line-to-line cementation. We used the Ein Bild Roentgen Analyse Femoral Component (EBRA-FCA) method to assess the subsidence of the femoral component. At the minimum 15-year follow-up, 73 patients were still alive and had not been revised at a mean of 17.3 years, 8 patients had been revised, 66 patients were deceased, and 8 patients were lost to follow-up. The mean subsidence of the entire series was 0.63 ± 0.49 mm (0 – 1.94 mm). When using a 1.5 mm threshold, only four stems were considered to have subsided. With revision of either component for any reason as the endpoint, the cumulative survival rate at 17 years was 90.5 ± 3.2% (95% CI, 84.2% to 96.8%). With radiological loosening of the femoral component as the endpoint, the cumulative survival rate at 17 years was 96.8 ± 3.1% (95% CI, 93.2% to 100%). This study demonstrated that, in most cases, a highly polished double tapered stem cemented line-to-line does not subside up to 18-year follow-up.
Introduction: Over the last 37 years I have performed more than 8000 primary and revision THRs. These include cemented, hybrid, and noncemented types of fixation. There are many preventable complications which include: infection, delayed wound healing, perforation or varus position of the implant, and suboptimal cement technique. Quality of function depends on restoring center of rotation, restoring offset, equal limb length, balancing soft tissue, and adequate pain control. Long-term success depends on durable fixation and reduced wear. Cement fixation into cortico-cancellous bone provides durable fixation. Discussion: We have a cohort at my practice of 370 total hip replacements. Fifty-three percent were cemented, 25% were hybrid, and 22% were noncemented. In another cohort of 253 cemented THR followed for a 10-year period, only two failures were found. One revision was for dislocation and the other was for loosening. I have found the Interlock system to have a very successful survivorship rate. I believe the reason for superior results is better polyethylene, better patient selection, and better surgical technique. I indicate cemented fixation for patients 60 years and older. I avoid if there is excessive bleeding and in a heavy, active patient.
Despite the best of technique, when faced with a sub-capital or per-trochanteric fracture, inevitably there are failures of proximal fixation. These situations provide unique challenges for the reconstructive surgeon. While there are specific issues related to either sub-capital or per-trochanteric fractures, there also are many commonalities. The causes of failure are nonunion, malunion, failure of fixation or avascular necrosis. In all cases, it is imperative to rule out infection. Since the surgery is now elective, the patient's medical status must be optimised prior to the intervention. Basic surgical principles apply to both fracture types. Use the old incision (if possible) and choose an approach that can be extensile. Of course, the old hardware needs to be removed – this task can be quite frustrating, so good preparation and patience is imperative. Retrieve old operative notes to identify the type of hardware so that any special tools needed are available. Hardware can be intra-osseous in location and excavation of the hardware may require bone osteotomy. These patients are at higher risk of post-operative dislocation, so absolute hip stability must be achieved and confirmed in the OR. Bigger heads and dual mobility options improve stability provided that the components are properly positioned and offset and leg length are restored. Subcapital fractures provide certain specific issues related to stem choice. While, my bias is towards THA because of better chance of complete pain relief, especially in community ambulators, certainly bipolar arthroplasties can be a satisfactory solution. Stem fixation can be either cemented or cementless. For per-trochanteric fractures in younger patients, repeat osteosynthesis should be considered if the femoral head is viable. Bone deformity – trochanteric overhang, shaft offset – may necessitate an osteotomy as part of the reconstruction. While proximal fixation primary type stems are often possible, distal fixation revision stems may be required. Any bone defects related to screw holes should be bypassed by the femoral component.
Generally cemented total hip arthroplasty (THA) has become an extremely successful operation with excellent long-term results. Although it always remained a popular choice for the elderly patients in many countries, recent trends show an increased use of noncemented stems in all age populations in many national registries. So far, there has been no clear age associated recommendation, when a cemented stem should be used. Described major complications including periprosthetic fractures are usually associated with age >75 years, in many registries. Uncemented stems perform better than cemented stems in recent registries; however, unrecognised intra-operative femoral fractures may be an important reason for early failure of uncemented stems. Experimental studies have indicated that intra-operative fractures do affect implant survival, it has been shown that intra-operative and direct post-operative fractures increase the relative risk of revision during the first 6 post-operative months significantly. In addition it has been clearly shown, that uncemented stems were more frequently revised due to periprosthetic fracture during the first 2 post-operative years than cemented stems. Based on the overall femoral bone quality, especially in female patients >70 years, cemented fixation has a lower fracture risk. Based on the implant fixation type: metaphyseal vs. diaphyseal of various uncemented stems, major attention should be drawn to the intra-operative bone quality during the broaching process, especially for metaphyseal fixation stem types. Although cementless distal fixation can be achieved in thick cortices still in many patients, the incidence of associated thigh pain needs to be considered for some implant types. Furthermore small femoral canals might generate certain implant-bone size mismatch in relation to the proximal femur. In any cemented THA, a proper cementing technique is of major importance to assure longevity of implant fixation. This also includes proper implant sizing/templating, ensuring an adequate cement mantle thickness, which might be restricted in a small diameter femur. The desired outcome is a cement interdigitation into cancellous bone for 2–3 mm and an additional mantle of 2 mm pure cement. Consequently proper planning in small diameter patients, prevents sizing problems, while in few cases special/individualised stem sizes might be considered.
Despite the best of technique when faced with a sub-capital or per-trochanteric fracture, inevitably there are failures of proximal fixation. These situations provide unique challenges for the reconstructive surgeon. While there are specific issues related to either sub-capital or per-trochanteric fractures, there also are many commonalities. The causes of failure are nonunion, malunion, failure of fixation or avascular necrosis. In all cases, it is imperative to rule out infection. Since the surgery is now elective, the patient's medical status must be optimised prior to the intervention. Basic surgical principles apply to both fracture types. Use the old incision (if possible) and choose an approach that can be extensile. Of course, the old hardware needs to be removed – this task can be quite frustrating, so good preparation and patience is imperative. Retrieve old OP notes to identify the type of hardware so that any special tools needed are available. Hardware can be intra-osseous in location and excavation of the hardware may require bone osteotomy. These patients are at higher risk of postoperative dislocation, so absolute hip stability must be achieved and confirmed in the OR. Bigger heads and dual mobility options improve stability provided that the components are properly positioned and offset and leg length are restored. Subcapital fractures provide certain specific issues related to stem choice. While, my bias is towards total hip arthroplasty because of better chance of complete pain relief, especially in community ambulators, certainly bipolar arthroplasties can be a satisfactory solution. Stem fixation can be either cemented or cementless. For per-trochanteric fractures in younger patients, repeat osteosynthesis should be considered if the femoral head is viable. Bone deformity – trochanteric overhang, shaft offset – may necessitate an osteotomy as part of the reconstruction. While proximal fixation primary type stems are often possible, distal fixation revision stems may be required. Any bone defects related to screw holes should be bypassed by the femoral component.
Cement is the commonest method used to fix femoral components in the UK. This is not surprising as in the UK cemented fixation has provided better results than cementless fixation. The results of cemented fixation do however depend on the design of the stem. Polished collarless tapered stems are now the most widely used stems in the UK. These stems subside within the cement mantle thus compressing the cement and cement-bone interface and preventing these from failing. They are thus very tolerant of poor quality cementing. As a result aseptic loosening is extraordinarily rare even in young active patients. Compared with cementless fixation cement is very forgiving. It can be used with ease whatever the anatomy of the proximal femur and whatever the bone quality. Correct leg length can also easily be achieved. Thigh pain does not occur and intra-operative fractures are very rare. The antibiotics in the cement decrease the incidence of infection. In addition cement provides an effective barrier to particulate debris and joint fluid under pressure. The only real disadvantage of cemented fixation is that it may take longer than cementless fixation. However this extra time spent is compensated by the cheaper implant costs.
Cemented total hip arthroplasty (THA) has become an extremely successful operation with excellent long-term results. Although showing decreasing popularity in North America, it always remained a popular choice for the elderly patients in Europe and other parts of the world. Various older and recent studies presented excellent long-term results, for cemented fixation of the cup as well as the stem. Besides optimal component orientation, a proper cementing technique is of major importance to assure longevity of implant fixation. Consequently a meticulous bone bed preparation assures the mechanical interlock between the implant component, cement and the final bone bed. Preoperative steps as proper implant sizing/ templating, ensuring an adequate cement mantle thickness, and hypotensive anesthesia, minimising bleeding at the bone cement interface, are of major importance. First the fossa pyriformis should be clearly identified, including the posterolateral entry point of the prosthesis. The femoral neck cut is usually 1.5cm to 2cm above the minor trochanter, based on the preoperative planning and implant type. Opening of the canal is done with an awl or osteotome, followed by any blunt tipped instrument, to follow the intramedullary direction. A box osteotome opens the lateral portion of the femoral neck, gently to preserve as much cancellous bone as possible. Sequential broaching follows carefully and according to the planning, to ensure preservation of 2mm to 3mm cancellous bone for interdigitation. Some systems might require over-broaching by one size. Trialing is done with the broach. Following, irrigation using a long nozzle pulsatile lavage, reduces the chance for fat embolism. A cement restrictor is then placed 1.5cm to 2cm distal to the tip of the stem, to ensure an adequate cement mantle distally. A second complete pulsatile irrigation of the canal follows, to minimise bleeding, followed by a dry sponge. Cement mixing is vacuum based in the meantime, usually 60–80g. We prefer the use of low dose antibiotic laden cement in our set up. Two to three minutes after mixing, the cement is applied rapidly in a retrograde technique, with a cement gun placing the nozzle tip against the cement restrictor. The gun is “pushed” out during the application, rather than being withdrawn from the canal. Proximal pressurization is first done by thumb, then with a proximal seal for 1 minute. The stem is inserted slowly using steady manual pressure, in the center of the cement mantle, however should never be impacted. The stem is aligned with the previously defined lateral entry point and is held in position until the cement hardens. The desired outcome is a cement interdigitation into cancellous bone for 2mm to 3mm and an additional mantle of 2mm pure cement.
Femoral components in total hip replacements fail in well-known ways. There is vertical sink, posterior rotation and pivot, either distal or mid-stem. In order to sink, the stem moves into valgus and then slides down the inside of the calcar. It does not cut through the calcar. To prevent sink and pivot, a canal filling stem is required. Canal fill prevents the stem from moving into valgus and, therefore, it will not sink. Two centimeters with complete canal fill is adequate in a primary stem. A long stem will give longer canal fill in a revision. Sharp distal flutes will prevent rotation. The distal end of the stem should be polished. One is looking for a distal stability, not distal fixation. If the isthmus is intact, a primary stem can be used. If the isthmus is damaged, a long stem is necessary. If the calcar is intact, a primary neck is adequate. If the calcar is missing down to the level of the lesser trochanter, a calcar replacement neck is required. If there is more than 70 millimeters of completely missing proximal femur, a structural allograft is required. If the proximal femur is damaged, the ability to place a sleeve or collar to seek the best bone available independently of the stem version is very helpful. No matter how poor the proximal bone quality is, it can be supplemented by cerclage wires. The implant will sink only if the cerclage wires break. The advantage of proximal fixation is that loading the proximal femur speeds recovery. The huge disadvantage of distal fixation is removal of the implant should it become necessary. My long term results for the S-ROM stem used in revision are now out over 20 years. There were 119 primary stems with a minimum follow up of 5 years with no revisions for aseptic loosening. There were 262 long stems used. Nine (3.7%) underwent aseptic loosening. Most of these were due to technical errors due to my inexperience in the learning process of revision surgery. Four were dependent on strut-grafts and should have been treated with structural allografts. There were seven cases with structural allografts. Three were revised. Again, these were largely from problems arising from inexperience. I believe proximal modularity with distal stability allows the vast majority of revision cases to be treated with proximal fixation.
The undulating pattern of the distal femur is well recognized. Radiographs do not always represent the full extent of the undulations. With recent increasing use of guided growth technique in the distal femur, it is important to define safe zones for screw placement. We performed an anatomical study on 26 cadaveric distal femoral epiphyses, ages 3–18 years. High resolution three-dimensional surface scans were obtained with a laser scanner, and were analyzed to determine the absolute height of the central physeal ridge, and the central physeal ridge height with respect to the highest points medially and laterally.Purpose
Method
Background. Cementless
The initial success of modern total hip arthroplasty can in large part be attributed to the reliable fixation of the femoral component with the use of acrylic bone cement. Early success with cement led to a common pathway of development in North America and the European countries. Much of the early to mid-term research concentrated on refinement of variables related to the methodology and technique of cement fixation. Scandinavian registries were subsequently able to report on improved survivorship with better cementing technique. The net effect has been standardisation towards a small number of cemented implants with good long-term outcomes representing the majority of stems implanted in Sweden, for example. In North America, during the mid-term development of THA in the late 1980's, the term “cement disease” was coined and the cemented THA saw a precipitous decline in use, now to the point where many American orthopaedic residents are completing training never having seen a cemented THA. Modern uncemented femoral components can now claim good long-term survivorship, perhaps now comparable to cemented fixation. However, this has come at a cost with respect to the premium expense applied to the implant itself as well as lineage of failed uncemented constructs. The last several years have seen a proliferation of uncemented implants, usually at a premium cost, with no demonstrated improvement in survivorship. Osteolysis has not been solved with uncemented implants and cement disease has largely been recognised as a misnomer. Long-term outcomes of cemented
To document and assess the available evidence regarding single bundle, hamstrings autograft preparation techniques for Anterior Cruciate Ligament reconstruction (ACLR) and provide graft preparation options for different clinical scenarios. Three online databases (Embase, PubMed and Ovid [MEDLINE]) were searched from database inception until April 10, 2021. The inclusion criteria were English language studies, human studies, and operative technique studies for single bundle hamstrings autograft preparation for ACLR. Descriptive characteristics, the number of tendons, number of strands, tendon length, graft length and graft diameter were recorded. The methodological quality was assessed using the Methodological Index for Non-Randomized Studies (MINORS) instrument and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system for non-randomized and randomized studies, respectively. The initial search yielded 5485 studies, 32 met the inclusion criteria. The mean MINORS score across all nonrandomized studies was 8.2 (standard deviation, SD 6.6) indicating an overall low quality of evidence. The mean MINORS score for comparative studies was 17.4 (SD 3.2) indicating a fair quality of evidence. The GRADE assessment for risk of bias in the randomized study included was low. There were 2138 knees in 1881 participants, including 1296 (78.1%) males and 363 (21.9%) females recorded. The mean age was 30.3 years. The mean follow-up time was 43.9 months when reported (range 16-55 months). Eleven studies utilized the semitendinosus tendon alone, while 21 studies used both semitendinosus and gracilis tendons. There were 82 (3.8%) two-strand grafts, 158 (7.4%) three-strand grafts, 1044 (48.8%) four-strand grafts, 546 (25.5%) five-strand grafts, and 308 (14.4%) six-strand grafts included. Overall, 372 (19.7%) participants had a single-tendon ACLR compared to 1509 (80.2%) participants who had a two-tendon ACLR. The mean graft diameter was 9.4mm when reported. The minimum semitendinosus and gracilis tendon lengths necessary ranged from 210-280mm and 160-280mm respectively. The minimum graft length necessary ranged from 63-120mm except for an all-epiphyseal graft in the paediatric population that required a minimum length of 50mm. The minimum femoral, tibial, and intra-articular graft length ranged from 15-25mm, 15-35mm and 20-30mm respectively. Thirteen studies detailed intra-operative strategies to increase graft size such as adding an extra strand or altering the tibial and/or