Aims. The aim of this study was to determine the risk of tibial eminence avulsion intraoperatively for bi-unicondylar knee arthroplasty (Bi-UKA), with consideration of the effect of implant positioning, overstuffing, and sex, compared to the risk for isolated medial unicondylar knee arthroplasty (UKA-M) and bicruciate-retaining total knee arthroplasty (BCR-TKA). Methods. Two experimentally validated finite element models of tibia were implanted with UKA-M, Bi-UKA, and BCR-TKA. Intraoperative loads were applied through the condyles, anterior cruciate ligament (ACL), medial collateral ligament (MCL), and lateral collateral ligament (LCL), and the risk of fracture (ROF) was evaluated in the spine as the ratio of the 95. th. percentile maximum principal elastic strains over the tensile yield strain of proximal tibial bone. Results. Peak tensile strains occurred on the anterior portion of the medial sagittal cut in all simulations. Lateral translation of the medial implant in Bi-UKA had the largest increase in ROF of any of the implant positions (43%). Overstuffing the joint by 2 mm had a much larger effect, resulting in a six-fold increase in ROF. Bi-UKA had ~10% increased ROF compared to UKA-M for both the male and female models, although the smaller, less dense female model had a 1.4 times greater ROF compared to the male model. Removal of anterior bone akin to BCR-TKA doubled ROF compared to Bi-UKA. Conclusion. Tibial eminence avulsion fracture has a similar risk associated with Bi-UKA to UKA-M. The risk is higher for smaller and less dense tibiae. To minimize risk, it is most important to avoid overstuffing the joint, followed by correctly positioning the medial implant, taking care not to narrow the bone island anteriorly. Cite this article: Bone Joint Res 2022;11(8):575–584

Aims. Little is known about the risk factors that predispose to a rupture of the posterior cruciate ligament (PCL). Identifying risk factors is the first step in trying to prevent a rupture of the PCL from occurring. The morphology of the knee in patients who rupture their PCL may differ from that of control patients. The purpose of this study was to identify any variations in bone morphology that are related to a PCL. Patients and Methods. We compared the anteroposterior (AP), lateral, and Rosenberg view radiographs of 94 patients with a ruptured PCL to a control group of 168 patients matched by age, sex, and body mass index (BMI), but with an intact PCL after a knee injury. Statistical shape modelling software was used to assess the shape of the knee and determine any difference in anatomical landmarks. Results. We found shape variants on the AP and Rosenberg view radiographs to be significantly different between patients who tore their PCL and those with an intact PCL after a knee injury. Overall, patients who ruptured their PCL have smaller intercondylar notches and smaller tibial eminences than control patients. Conclusion. This study shows that differences in the shape of the knee are associated with the presence of a PCL rupture after injury. A smaller and more sharply angled intercondylar notch and a more flattened tibial eminence are related to PCL rupture. This suggests that the morphology of the knee is a risk factor for sustaining a PCL rupture. Cite this article: Bone Joint J 2019;101-B:1058–1062

Purpose: To determine the outcome following anterior tibial spine avulsion in skeletally mature patients. Summary: The study group comprised 83 knees with anterior tibial spine avulsion. The mean age of patients at injury was 35. Twenty knees with displaced tibial spine fractures were treated with fixation of the tibial spine and 63 patients with undisplaced or minimally displaced fractures were treated non-operatively. Twenty two percent of the non operatively managed knees developed symptomatic instability and 10% of knees treated with tibial spine fixation developed instability (p=0.22). Stiffness was more common in knees treated with tibial spine fixation than in knees managed nonoperatively (60% vs 19%, p < 0.0005). There was a tendency for increased stiffness in older patients treated with surgical fixation of the tibial spine. Conclusion: Tibial spine fracture in skeletally mature patients is associated with significant risk of knee stiffness and instability

Aim: To review the outcomes for avulsion fractures of the tibial spine in children managed by arthroscopic internal fixation using a canulated screw. Materials & Methods: A retrospective review was performed of 8 tibial spine avulsion fractures in children managed operatively by arthroscopic canulated screw fixation over a 4 year period. All fractures were graded grade III or IV (Meyer and McKeevers) in severity. Notes and radiographs were reviewed and Lysholm scores were obtained. The average age of our patients was 10.6 years and the average duration of follow up was 23.6 months (Range: 3–52 months). The average Lysholm score achieved was 88.9 (median 94.5, range 61–100) with the score demonstrably improving after the first year from injury. Bony healing was seen in all cases. One patient needed manipulation under anaesthesia to realize full movement. Conclusions: On the basis of these results, we recommend arthroscopic canulated screw fixation as the treatment of choice for tibial spine avulsions. It takes over a year, however, to achieve optimal results. This series represents the largest collection of these uncommon injuries hitherto reported from the UK

Introduction: Avulsion fractures of the anterior tibial spine are not so common. The best form of treatment for displaced fractures is still debatable. Aims: We aimed to analyze the results of different forms of internal fixation for avulsion fractures of the anterior tibial spine. Material and Methods: Twenty-five patients with avulsion fractures of the anterior tibial spine had open reduction and internal fixation with different implants (AO screw, Herbert screw, stainless steel wire loop and absorbable stitch) and techniques. The mean follow up period was 3.66 years. They were evaluated clinically and radiologically, using KT 1000 arthrometer for ACL laxity and goniometer for range of movements. The outcome was measured using Lysholm Knee Score. Results: Significant residual anterior laxity despite adequate fracture union was a common finding. Maximum ACL laxity was seen in adults in whom absorbable stitches had been used and they had a corresponding lower Lysholm score. Significant migration of the Herbert screws was noted in two of five patients in which it was used. Five of the eight patients with higher Lysholm score had AO screw fixation. Three patients with steel wire loop for stabilization of the fracture also had better results comparatively. Three individuals who had their knee immobilised in 25°–50° of flexion developed fixed flexion deformities, which took 12–18 months to recover. Conclusions: The use of absorbable stitches as the primary method of fixation for avulsion fractures of the tibial spine should be avoided in adults. Herbert screw in this situation has a tendency to migrate. AO screws and non-absorbable loop yields better functional outcome. Immobilization of the knee in excessive flexion leads to prolonged fixed flexion deformity. Early range of movements can be achieved by replacing cast with a brace allowing flexion up to 90 degrees

Abstract. Background. Anterior cruciate ligament (ACL) injuries with coinciding posterolateral tibial plateau (PLTP) depression fractures are rare. According to the most up to date literature, addressing the PLTP is crucial in preventing failure of the ACL. However, the surgical management of these injuries pose a great challenge to orthopaedic surgeons, given the anatomical location of the depressed PTP fragment. We report a case of a 17-year-old patient presenting to our department with this injury and describe a novel fixation method, that has not been described in the literature. Surgical Technique. A standard 2-portal arthroscopy is used to visualise the fractures. The PLTP is addressed first. With the combined use of arthroscopy and fluoroscopy, a guide pin is triangulated from the anteromedial aspect of the tibia, towards the depressed plateau fragment. Once the guide pin is approximately 1cm from the centre of the fragment, it is over-drilled with a cannulated drill, and simultaneously bluntly punched up to its original anatomical location. Bone graft is then used to fill the void, supported by two subchondral screws. Both fluoroscopy and arthroscopy are used to confirm adequacy of fixation. Finally, the tibial spine avulsion fracture is repaired arthroscopically using the standard suture bridging technique. Conclusion. We describe a novel, one-stage, minimally invasive approach that addresses both the ACL injury and PLTP fracture. We highlight the advantages of utilising this approach and functional outcomes

Purpose of the study: We describe a new modified arthroscopic technique of surgically treating avulsion fractures of the tibial eminence using the Scorpion device (Arthrex, Naples, FL). Methods and results: A 57 year-old female who sustained a type II fracture of the tibial spine was treated with arthroscopic fracture fixation using the Scorpion device to place a whip stitch into the substance of the anterior cruciate ligament (ACL). Tibial tunnels were made on the anteromedial aspect of the tibia using the Acufex ACL guide (Smith and Nephew, Mansfield, MA) and the sutures were passed through these tunnels and tied over a bony bridge. At 6 months after surgery, the patient was asymptomatic and had returned to her daily activities. She had regained full range of movement and had a clinically stable knee, confirmed on KT 2000 arthrometer. Radiographs showed anatomic reduction and fracture union. Conclusion: The Scorpion device which is commonly used in arthroscopic shoulder surgery provides significant advantages as it can be used arthroscopically to place a whip stitch in the substance of the ACL. The hook at its end can be used to retrieve suture loop from the joint, thus reducing instrumentation and operating time. It is a user friendly arthroscopic technique that restores the necessary tension in the ACL, provides stable fracture fixation, and also results in a cosmetic end result

Forty-five patients with fractures of the tibial spine were reviewed 3 to 10 years after injury in order to determine the degree of residual laxity of the cruciate or collateral ligaments. After fractures which had been partially or completely displaced, some anterior cruciate laxity was evident, even if patients were asymptomatic. It was also found that an anatomical reduction did not prevent either laxity or some loss of full extension of the knee

Purpose Of The Study: Avulsion fractures of the anterior tibial spine are uncommon injury and we have evaluated the results in-patients who have undergone arthrotomy and fixation of the fracture. Material & Method: Twenty five patients were followed up between 21–108 months (mean 44 months) after the operation. They were evaluated clinically, radiologically and the residual ACL laxity was measured with KT 1000. Lysholm scoring scale has been used to assess the outcome. Eight fractures were fixed with a single AO screw; 5 with Herbert screws; 4 with a steel wire loop and 8 with absorbable stitch. Results: Significant residual anterior laxity despite adequate fracture union was a common finding. The ACL laxity was maximum in adults in whom absorbable stitch had been used to fix the fracture and they had a corresponding lower Lysholm score. In 2 out of the 5 patients where Herbert screws had been used there was significant migration of the screws. Additional articular damage was observed in 3 patients who were pedestrians hit by a car. All 3 ended up with restricted knee movements and poor results. Three individuals who had their knee immobilised in 250–500 of flexion developed flexion deformities, which took 12–18 months to recover. Conclusions: We recommend that use of absorbable stitches as a method of fixation be avoided in adults. Herbert screws in this situation have a tendency to migrate. AO screws or a non-absorbable loop should be used were possible. Immobilisation of the knee in excessive flexion leads to prolonged flexion deformity and we recommend immobilising the knee in no more than 100 of flexion

We reviewed 19 adults and 12 children who had been treated for avulsion fractures of the tibial spine. Adult injuries have not previously been reported at length; most were caused by road-traffic accidents, and 68% were associated with other injuries, of which 58% were around the knee. The higher incidence of associated injuries in adults as compared with children, indicates that the injury is the result of greater energy and perhaps a different mechanism. The worse outcome in some adults was due to other associated intra-articular fractures and tears of the medial collateral ligament. Arthroscopy is useful in both diagnosis and treatment. Early accurate diagnosis and the correct treatment produce a good outcome

Aim: The purpose of study was to analyse osseous changes of tibial spine in radiographs of knees with aplasia of cruciate ligament. Methods: 13 patients with aplasia of cruciate ligament and respective x-rays were examined and analysed. Diagnosis were proofen by MRI or Arthroscopy. Moreover we checked patients with anterior and complete aplasia of cruciate ligament (s) separately. Results: We found typical signs of hypolasia and aplasia of intercondylar eminence in radiagraphs which correlate with anterior or complete aplasia of cruciate ligaments. These changes we classiþed in 3 types. Conclusion: Using this classiþcation it is possible to get a strong indication for aplasia of cruciate ligament only on the basis of x-rays

The April 2023 Children’s orthopaedics Roundup. 360. looks at: CT scan of the ipsilateral femoral neck in paediatric shaft fractures; Meniscal injuries in skeletally immature children with tibial eminence fractures: a systematic literature review; Post-maturity progression in adolescent idiopathic scoliosis curves of 40° to 50°; Prospective, randomized Ponseti treatment for clubfoot: orthopaedic surgeons versus physical therapists; FIFA 11+ Kids: challenges in implementing a prevention programme; The management of developmental dysplasia of the hip in children aged under three months: a consensus study from the British Society for Children's Orthopaedic Surgery; Early investigation and bracing in developmental dysplasia of the hip impacts maternal wellbeing and breastfeeding; Hip arthrodesis in children: a review of 26 cases with a mean of 20 years’ follow-up

Abstract. Background. Little scientific evidence is available regarding the effect of knee joint line obliquity (JLO). Methods. 10 fresh-frozen human cadaveric knees were axially loaded to 1500 N in a materials testing machine with the joint line tilted 0, 4, 8, and 12 degrees varus and valgus, at 0, and 20 degrees of knee flexion. The mechanical compression axis was aligned to the centre of the tibial plateau. Contact pressures / areas were recorded by sensors inserted between the tibia and femur below the menisci. Changes in relative femoral and tibial position in the coronal plane were obtained by an optical tracking system. Results. medial and lateral JLO caused significant tibiofemoral subluxation and pressure distribution changes. Medial (varus) JLO caused the femur to sublux medially down the coronal slope of the tibial plateau, and vice versa for lateral (valgus) downslopes (P=0.01). Areas of peak pressure moved 12 mm and 8 mm across the medial and lateral condyles, onto the ‘downhill’ meniscus and the ‘uphill’ tibial spine. Changes in JLO had only small effects on maximum contact pressures. Conclusion. A change of JLO during load bearing caused significant mediolateral tibiofemoral subluxation. The femur slid down the slope of the tibial plateau to abut the tibial eminence and also to rest on the downhill meniscus. Clinical Relevance. These results provide important information for understanding the consequences of creating coronal JLO and for clinical practice in terms of osteotomy planning regarding the effect on JLO

Abstract. Objectives. There is renewed interest in bi-unicondylar arthroplasty (Bi-UKA) for patients with medial and lateral tibiofemoral osteoarthritis, but a spared patellofemoral compartment and functional cruciate ligaments. The bone island between the two tibial components may be at risk of tibial eminence avulsion fracture, compromising function. This finite element analysis compared intraoperative tibial strains for Bi-UKA to isolated medial unicompartmental arthroplasty (UKA-M) to assess the risk of avulsion. Methods. A validated model of a large, high bone-quality tibia was prepared for both UKA-M and Bi-UKA. Load totalling 450N was distributed between the two ACL bundles, implant components and collateral ligaments based on experimental and intraoperative measurements with the knee extended and appropriately sized bearings used. 95th percentile maximum principal elastic strain was predicted in the proximal tibia. The effect of overcuts/positioning for the medial implant were studied; the magnitude of these variations was double the standard deviation associated with conventional technique. Results. For all simulations, strains were an order of magnitude lower than that associated with bone fracture. Highest strain occurred in the spine, under the anteromedial ACL attachment, adjacent to transverse overcut of the medial component. Consequently, Bi-UKA had little effect on strain: <10% increases were predicted when compared to UKA-M with equivalent medial cuts/positioning. However, surgical overcutting/positional variation that resulted in loss of anteromedial bone in the spine increased strain. The biggest increase was for lateral translation of the medial component: 44% and 42% for UKA-M and Bi-UKA, respectively. Conclusions. For a large tibia with high bone quality, Bi-UKA with a well-positioned lateral implant had no tangible effect on the risk of tibial eminence avulsion fracture compared to UKA-M. Malpositioning of the medial component that removes bone from the anterior spine could prove problematic for smaller tibiae. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

With medial unicompartmental osteoarthritis (OA) there is occasionally a full-thickness ulcer of the cartilage on the medial side of the lateral femoral condyle. It is not clear whether this should be considered a contraindication to unicompartmental knee replacement (UKR). The aim of this study was to determine why these ulcers occur, and whether they compromise the outcome of UKR. Case studies of knees with medial OA suggest that cartilage lesions on the medial side of the lateral condyle are caused by impingement on the lateral tibial spine as a result of the varus deformity and tibial subluxation. Following UKR the varus and the subluxation are corrected, so that impingement is prevented and the damaged part of the lateral femoral condyle is not transmitting load. An illustrative case report is presented. Out of 769 knees with OA of the medial compartment treated with the Oxford UKR, 59 (7.7%) had partial-thickness cartilage loss and 20 (2.6%) had a full-thickness cartilage deficit on the medial side of the lateral condyle. The mean Oxford Knee Score (OKS) at the last follow-up at a mean of four years was 41.9 (13 to 48) in those with partial-thickness cartilage loss and 41.0 (20 to 48) in those with full-thickness loss. In those with normal or superficially damaged cartilage the mean was 39.5 (5 to 48) and 39.7 (8 to 48), respectively. There were no statistically significant differences between the pre-operative OKS, the final review OKS or of change in the score in the various groups. We conclude that in medial compartment OA, damage to the medial side of the lateral femoral condyle is caused by impingement on the tibial spine and should not be considered a contraindication to an Oxford UKR, even if there is extensive full-thickness ulceration of the cartilage

The rotational alignment of the tibia is an unresolved issue in knee replacement. A poor functional outcome may be due to malrotation of the tibial component. Our aim was to find a reliable method for positioning the tibial component in knee replacement. CT scans of 19 knees were reconstructed in three dimensions and orientated vertically. An axial plane was identified 20 mm below the tibial spines. The centre of each tibial condyle was calculated from ten points taken round the condylar cortex. The tibial tubercle centre was also generated as the centre of the circle which best fitted eight points on the outside of the tubercle in an axial plane at the level of its most prominent point. The derived points were identified by three observers with errors of 0.6 mm to 1 mm. The medial and lateral tibial centres were constant features (radius 24 mm (. sd. 3), and 22 mm (. sd. 3), respectively). An anatomical axis was created perpendicular to the line joining these two points. The tubercle centre was found to be 20 mm (. sd. 7) lateral to the centre of the medial tibial condyle. Compared with this axis, an axis perpendicular to the posterior condylar axis was internally rotated by 6° (. sd. 3). An axis based on the tibial tubercle and the tibial spines was also internally rotated by 5° (. sd. 10). Alignment of the knee when based on this anatomical axis was more reliable than either the posterior surfaces or any axis involving the tubercle which was the least reliable landmark in the region

Purpose: The purpose of this study was to examine how the “ideal” tibial nail insertion point varies with tibial rotation and to determine what radiographic landmarks can be used to identify the most suitable rotational view for insertion of a tibial intramedullary nail. Methods: Twelve cadaveric lower limb specimens with intact soft tissues around the knee and ankle joints were used. A 2.0mm Kirschner wire was placed in the center of the anatomic safe zone and centered on the tibial shaft. The leg was rotated and imaged using a fluoroscopic C-arm until the K-wire was positioned just medial to the lateral tibial spine (defined as the neutral anteroposterior radiograph). The leg was then fixed and radiographs were taken in 5 degree increments by rotating the fluoroscope internally and externally (in total, a 50 degree arc). Following this a second K-wire was placed in 5 mm increments both medially and laterally and the fluoroscope rotated until this second K-wire was positioned just medial to the lateral tibial spine. Radiographs were digitized for measurements. Results: Given the presence of a 30 degree rotational arc through which the radiograph appeared anteroposterior, it was possible to improperly translate the start point up to 15 mm. Relative external rotation of the image used for nail placement led to a medial insertion site when using the lateral tibial spine as the landmark. A line drawn at the lateral edge of the tibial plateau to bisect the fibula head correlated with an entry point that was central or up to 5 mm lateral to the ideal entry point. The use of a fibula head bisector line avoided a medial insertion point. Conclusions: Rotation of the tibia may result in up to 15 mm of translation of the start point that may be unrecognized. Relative external rotation of the film used for nail placement leads to medial insertion sites when using the lateral tibial spine as a landmark. The fibula head bisector line can be used to avoid choosing external rotation views and thus avoid medial insertion points

The December 2015 Children’s orthopaedics Roundup. 360 . looks at: Paediatric femoral fractures: a single incision nailing?; Lateral condylar fractures: open or percutaneous?; . Forearm refracture: the risks; Tibial spine fractures; The child’s knee in MRI; The mechanics of SUFE; Idiopathic clubfoot

Tibial eminence fractures were historically thought of as a condition of skeletal immaturity. Increasingly this injury has been recognized in adults. The aim was to report on the demographics, mechanism, treatment and outcomes of this injury in adult and paediatric patients. A retrospective review of all patients presenting to Dunedin Hospital, for management of a displaced tibial eminence fracture, between 1989 and 2009. 19 cases were identified, 10 skeletally mature and 9 skeletally immature. Alpine skiing with a forced flexion and rotation injury accounted for 7 cases, primarily adult females (5 cases). A hyper-extension and rotation injury accounted for 7 cases, primarily in skeletally immature males (4 cases), while direct trauma accounted for 5 cases, primarily males (4 cases). Associated injuries were more commonly seen in adults and those with high energy trauma. Stiffness was the most common complication (10 cases). Tibial spine fractures are more common in adults than previously thought. Female skiers appear to be a group at particular risk. Our most common complication was stiffness. Early range of motion is essential to reduce the problem of stiffness and extension impingement. Laxity is an infrequent problem in adults and children

This study was designed to identify the radiological changes of the knee that correlated with an unfavorable outcome when treated with an intra-articular knee viscoelastic supplementation. A prospective cohort of 60 patients receiving a standard course of intra-articular knee viscoelastic supplementation with a commercial uncrosslinked hyaluronic acid derivative of an intermediate molecular weight were studied. Follow-up was for 12 weeks post treatment with clinical improvement measured using the Western Ontario and McMasters Universities Osteoarthritis Index. Radiographs of the relevant knee were viewed and graded for the severity of joint space, osteophyte, tibial spine, sclerosis, cyst formation, alignment and general severity by an observer blinded to the outcome of the treatment. There were no appreciable differences noted in the age, sex, length of follow up, prior treatment, the severity of symptoms before treatment and number of intra-articular injections given per course in each radiographic category identified. There was a significant amount of improvement in patients with a minor loss of medial and lateral joint space in all outcome measures. Minimal changes in tibial spine and global appearance also indicated a positive outcome in stiffness, pain and overall improvement. Thus, patients with moderate to severe osteoarthritic changes in joint space on radiographic examination would not significantly benefit from intra-articular knee viscoelastic supplementation. In addition, we feel that changes in the tibial spine and global appearance are not reviewed consistently enough to be included as part of our recommendation. As such, we conclude that only patients with a minimal to mild loss in joint space on radiological examination should form part of the target group who are likely to benefit from intra-articular knee viscoelastic supplementation