Aims. Slipped upper femoral epiphysis (SUFE) has well documented biochemical and mechanical risk factors. Femoral and acetabular morphologies seem to be equally important. Acetabular retroversion has a low prevalence in asymptomatic adults. Hips with dysplasia, osteoarthritis, and Perthes’ disease, however, have higher rates, ranging from 18% to 48%. The aim of our study was to assess the prevalence of acetabular retroversion in patients presenting with SUFE using both validated radiological signs and tomographical measurements. Methods. A retrospective review of all SUFE surgical cases presenting to the Royal Children’s Hospital, Melbourne, Australia, from 2012 to 2019 were evaluated. Preoperative plain radiographs were assessed for slip angle, validated radiological signs of retroversion, and standardized postoperative CT scans were used to assess cranial and mid-acetabular version. Results. In all, 116 SUFEs presented in 107 patients who underwent surgical intervention; 47 (52%) were male, with a mean age of 12.7 years (7.5 to 16.6). Complete radiological data was available for 91 patients (99 hips) with adequate axial CT imaging of both hips. Overall, 82 patients (82%) underwent pinning in situ (PIS), with subcapital realignment surgery (SRS) performed in 17 patients (18%) (slip angles > 75°). Contralateral prophylactic PIS was performed in 72 patients (87%). On the slip side, 62 patients (68%) had one or more radiological sign of retroversion. Tomographical acetabular retroversion was more pronounced cranially than caudally of the acetabulum on both the affected side and the contralateral side (p < 0.001) as expected in the normal population. Increasing severity of the slip was found to be directly proportional to the degree of reduction in cranial and central acetabular version (p < 0.05) in the SUFE hips. Conclusion. Acetabular retroversion is more prevalent in patients with SUFE than previously reported, and have been shown be correlated to the severity of the slip presentation. The presence of radiological signs of acetabular retroversion could be used to justify prophylactic contralateral pinning. Cite this article: Bone Jt Open 2022;3(2):158–164

Aims. The aim of this study was to determine the association between knee alignment and the vertical orientation of the femoral neck in relation to the floor. This could be clinically important because changes of femoral neck orientation might alter chondral joint contact zones and joint reaction forces, potentially inducing problems like pain in pre-existing chondral degeneration. Further, the femoral neck orientation influences the ischiofemoral space and a small ischiofemoral distance can lead to impingement. We hypothesized that a valgus knee alignment is associated with a more vertical orientation of the femoral neck in standing position, compared to a varus knee. We further hypothesized that realignment surgery around the knee alters the vertical orientation of the femoral neck. Methods. Long-leg standing radiographs of patients undergoing realignment surgery around the knee were used. The hip-knee-ankle angle (HKA) and the vertical orientation of the femoral neck in relation to the floor were measured, prior to surgery and after osteotomy-site-union. Linear regression was performed to determine the influence of knee alignment on the vertical orientation of the femoral neck. Results. The cohort included 147 patients who underwent knee realignment-surgery. The mean age was 51.5 years (SD 11). Overall, 106 patients underwent a valgisation-osteotomy, while 41 underwent varisation osteotomy. There was a significant association between the orientation of the knee and the coronal neck-orientation. In the varus group, the median orientation of the femoral neck was 46.5° (interquartile range (IQR) 49.7° to 50.0°), while in the valgus group, the orientation was 52.0° (IQR 46.5° to 56.7°; p < 0.001). Linear regression analysis revealed that HKA demonstrated a direct influence on the coronal neck-orientation (β = 0.5 (95% confidence interval (CI) 0.2 to 0.7); p = 0.002). Linear regression also showed that realignment surgery was associated with a significant influence on the change in the coronal femoral neck orientation (β = 5.6 (95% CI 1.5 to 9.8); p = 0.008). Conclusion. Varus or valgus knee alignment is associated with either a more horizontal or a more vertical femoral neck orientation in standing position, respectively. Subsequently, osteotomies around the knee alter the vertical orientation of the femoral neck. These aspects are of importance when planning osteotomies around the knee in order to appreciate the effects on the adjacent hip joint. The concept may be of even more relevance in dysplastic hips. Cite this article: Bone Jt Open 2021;2(12):1057–1061

Abstract. Introduction. The paediatric population present unique challenges to the knee surgeon, particularly when treating recurrent patellofemoral instability(PFI), the management of which is poorly standardised. Through the EPPIC BASK National Trainee Collaborative, we aimed to identify which procedures (and in which combination) are being used to surgically manage recurrent PFI in skeletally immature patients across the UK. Methods. A retrospective national service evaluation via a trainee collaborative analysing local trust data between 1st January 2014 and 31st December 2019. Data from institutions registered for EPPIC was compiled and compared to the national guidelines for adults. Results. A total of 333 patients were classified as skeletally immature(radiologically open physes) across 28 hospitals. Mean age was 14.1 years(+/- 4.5) with 64.9% being female. Mean number of procedures performed was 11.9 (+/-16.4). Isolated medial patellofemoral ligament reconstruction (MPFLR) was the most common procedure, performed in 65.8% of patients. Combined MPFLR and TTO was undertaken in 13.2% of patients. Proximal realignment surgery was performed in 5.1% of patients. Lateral releases were performed in 18.3% of patients with 8.4% performed in isolation. Conclusion. This study highlights the national variation in surgical treatment of PFI in skeletally immature patients. The guidance for adults cannot be applied universally to the skeletally immature, and it not always acceptable to delay treatment until physes close. This lack of standardisation within the UK in the management of recurrent PFI in skeletally immature patients highlights the need for a national consensus in appropriate surgical management of this patient population

Background: No studies exist about the long-term correlation of patellofemoral osteoarthrosis to poor outcome after traditional realignment surgery for chronic patellofemoral instability. The objective of this study was to evaluate the recurrent instability and symptomatic osteoarthrosis over a long follow-up period. Methods: Fifty-two patients underwent distal realignment surgery for chronic patellar instability, 28 with Roux-Goldthwait procedure and 24 with Krogius procedure. A follow-up evaluation was performed at a mean 12 years (range, 8 to 22 years) after surgery, in which 39 of 52 patients participated. Recurrent instability and osteoarthrotic characteristics were evaluated by plain radiographs and magnetic resonance images obtained at follow-up. The original hospital data were reviewed to assess patients’ background. Subjective symptoms were assessed with patellofemoral scores. Results: Of the 39 controlled patients, 10 had chronic patellar instability, including 4 patients who underwent reoperation during follow-up. The mean patient age at follow-up was 33 years (range, 26 to 43). Patellofemoral full-thickness cartilage lesions were found on MRI in 29 (75%) of patients and all of the patients had mild lesions. A joint space narrowing was present in 6 cases in plain radiographs indicating severe patellofemoral osteoarthrosis. Only 48% of the patients reported satisfaction with the patellar stability and anterior knee symptoms and the unsatisfactory result was associated with patellofemoral osteoarthrosis (P=0.05). The mean Kujala score was 83 (range 52–100) points. The surgical technique employed did not affect the overall outcome. Conclusion: The long-term outcome of traditional realignment surgery for chronic patellofemoral instability seemed to be strongly associated with patellofemoral osteoarthrosis. Despite the relatively rare occurrence of recurrent instability, less than half of patients achieved a satisfactory result. Patellofemoral osteoarthrosis seems to be the long-term consequence in patients treated with traditional surgical procedures for patellar instability. In future studies focusing on patellar stability, preventive methods against the development of patellofemoral osteoarthrosis should be emphasized

Abstract. Objective. To assess the prevalence of acetabular retroversion in patients presenting with Slipped Upper Femoral Epiphysis using both validated radiological signs and CT-angle measurements. Methods. A retrospective review of all cases involving surgical management for acute SUFE presenting to the Royal Children's Hospital, Melbourne were assessed from 2012–2018. Pre-operative plain radiographs were assessed for slip angle, validated radiological signs of retroversion (post wall/crossover/ischial spine sign) and standardised post-operative CT Scans were used to assess cranial and mid-acetabular version. Results. 116 SUFEs presented in 107 patients who underwent surgical intervention; 47 females and 60 boys, with an average age of 12.7 years (range 7.5–16.6 years). Complete radiological data was available for 91 patients (99 hips) with adequate axial CT imaging of both hips. 82% patients underwent pinning in situ (PIS) with subcapital realignment surgery (SRS) performed in 18% (slip angles >75°). Contralateral prophylactic hip PIS was performed in 72 patients (87%). On the slip side, 68% of patients had 1 or more radiological signs of retroversion in the slipped hip, with 60% on the contralateral side. The mean cranial and mid-acetabular version measurements were −8°(range −30 – 8°) and 10.5°(range −10 – 25°), respectively. Conclusions. Acetabular retroversion is rare in the normal population with studies reports ranging from 0–7%. This study showed an increased prevalence of 68% in SUFE patients, which is likely to be a primary anatomical abnormality, subsequently increasing the shear forces across the proximal femoral growth plate due to superior over-coverage. The resulting CAM lesion from SUFE in combination with the pincer lesion due to retroversion can lead to premature hip impingement and degeneration. Further larger studies are required to assess if acetabular retroversion is a true risk factor, and its role in helping guide management including prophylactic pinning. Declaration of Interest. (b) declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported:I declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project

Biomedical imaging is essential in the diagnosis of musculoskeletal pathologies and postoperative evaluations. In this context, Cone-Beam technology-based Computed Tomography (CBCT) can make important contributions in orthopaedics. CBCT relies on divergent cone X-rays on the whole field of view and a rotating source-detector element to generate three-dimensional (3D) volumes. For the lower limb, they can allow acquisitions under real loading conditions, taking the name Weight-Bearing CBCT (WB-CBCT). Assessments at the foot, ankle, knee, and at the upper limb, can benefit from it in situations where loading is critical to understanding the interactions between anatomical structures. The present study reports 4 recent applications using WB-CBCT in an orthopaedic centre. Patient scans by WB-CBCT were collected for examinations of the lower limb in monopodal standing position. An initial volumetric reconstruction is obtained, and the DICOM file is segmented to obtain 3D bone models. A reference frame is then established on each bone model by virtual landmark palpation or principal component analysis. Based on the variance of the model point cloud, this analysis automatically calculates longitudinal, vertical and mid-lateral axes. Using the defined references, absolute or relative orientations of the bones can be calculated in 3D. In 19 diabetic patients, 3D reconstructed bone models of the foot under load were combined with plantar pressure measurement. Significant correlations were found between bone orientations, heights above the ground, and pressure values, revealing anatomic areas potentially prone to ulceration. In 4 patients enrolled for total ankle arthroplasty, preoperative 3D reconstructions were used for prosthetic design customization, allowing prosthesis-bone mismatch to be minimized. 20 knees with femoral ligament reconstruction were acquired with WB-CBCT and standard CT (in unloading). Bone reconstructions were used to assess congruency angle and patellar tilt and TT-TG. The values obtained show differences between loading and unloading, questioning what has been observed so far. Twenty flat feet were scanned before and after Grice surgery. WB-CBCT allowed characterization of the deformity and bone realignment after surgery, demonstrating the complexity and multi-planarity of the pathology. These applications show how a more complete and realistic 3D geometric characterization of the of lower limb bones is now possible in loading using WB-CBCT. This allows for more accurate diagnoses, surgical planning, and postoperative evaluations, even by automatisms. Other applications are in progress

Osteoarthritis (OA), characterised by pain, disability and joint degeneration, is common and has no cure. Prevalence of severe radiographic knee OA is 19% in over 45's and 50% in over 75's in the US and Europe. Abnormal joint loading, or injury, increase risk of OA. We have discovered that glutamatergic signalling is mechanically regulated and glutamate receptors (GluR) drive inflammation, degeneration and pain representing potential drug targets in osteoarthritic joints. Joints from OA and knee injured patients, and rodent models of arthritis, show increased synovial fluid glutamate concentrations and abundant GluR expression. Since AMPA/kainate GluRs regulate IL-6, a critical mediator of arthritic degeneration, we tested protective effects of the AMPA/KA GluR antagonist, NBQX in animal models of arthritis. In rodent antigen induced arthritis, and osteoarthritis (meniscal transection and anterior cruciate ligament rupture), NBQX reduced joint swelling, degeneration and pain, exceeding anti-degenerative effects of other drugs tested similarly. 3D osteocyte/osteoblast co-cultures and human bone samples taken from patients undergoing high tibial osteotomy joint realignment surgery, revealed underlying cellular mechanisms mediated by bone cells. Related drugs, already used in humans for epilepsy and migraine, represent a repurposing opportunity and are effective in our models of arthritis

Introduction. Epidemiologic studies indicate that isolated patellofemoral (PF) arthritis affects nearly 10% of the population over 40 years of age, with a predilection for females. A small percentage of patients with PF arthritis may require surgical intervention. Surgical options include non-arthroplasty procedures (arthroscopic debridement, tibial tubercle unloading procedures, cartilage restoration, and patellectomy), and patellofemoral or total knee arthroplasty (PFA or TKA). Historically, non-arthroplasty surgical treatment has provided inconsistent results, with short-term success rates of 60–70%, especially in patients with advanced arthritis. Although TKA provides reproducible results in patients with isolated PF arthritis, it may be undesirable for those interested in a more conservative, kinematic-preserving approach, particularly in younger patients, who may account for nearly 50% of patients undergoing surgery for PF arthritis. Due to these limitations, patellofemoral arthroplasty (PFA) has become utilised more frequently over the past two decades. Indications for PFA. The ideal candidate for PFA has isolated, non-inflammatory PF arthritis resulting in “anterior” pain and functional limitations. Pain should be retro- and/or peri-patellar and exacerbated by descending stairs/hills, sitting with the knee flexed, kneeling and standing from a seated position. There should be less pain when walking on level ground. Symptoms should be reproducible during physical examination with squatting and patellar inhibition testing. An abnormal Q-angle or J-sign indicate significant maltracking and/or dysplasia, particularly with a previous history of patellar dislocations. The presence of these findings may necessitate concomitant realignment surgery with PFA. Often, patients with PF arthritis will have significant quadriceps weakness, which should be treated with preoperative physical therapy to prevent prolonged postoperative pain and functional limitations. Tibiofemoral joint pain suggests additional pathology, which may not be amenable to PFA alone. Conclusion. PFA is effective for the treatment of arthritis localised to the PF compartment. Outcomes can be optimised with proper patient selection, meticulous surgical technique, and selection of an onlay-style implant that can be positioned perpendicular to the AP axis of the femur. Minimizing the risk of patellar instability by using onlay-design PFAs has enhanced mid- and long-term results, and leaves progressive tibiofemoral arthritis as the primary failure mechanism beyond 10–15 years

This study is a prospective analysis of clinical outcome in 201 consecutive patients treated with medial patellofemoral ligament reconstruction using an autologous semitendinosus graft between October 2005 and January 2011. Patients received pre and post-operative clinical evaluation, radiological assessment and outcome scoring systems. 193 patients (92 male, 119 female) underwent 211 procedures, with mean age 26 (16–49) and follow-up 16 months (6–42 months). Indications were atraumatic recurrent patella dislocation (68%), traumatic recurrent dislocation (22.8%), instability (5%), single dislocation (2.7%) and anterior knee pain (1.4%). Trochlea dysplasia was moderate in 57% and mild in 35%. There have been no recurrent dislocations/ subluxations. 10 patients have required further surgery. The mean pre-op Kujala Scores were 55 (SE 5.21) and post-op scores improved to mean 82 (31–100) (SE 1.18)(p < 0.001). This improvement and significance is mirrored with Oxford (27 to 41), WOMAC (76 to 93), Fulkerson (53 to 83), IKDC (46 to 75), Tegner (4.1 to 5.3) and SF12 (38 to 51) scores (p < 0.005). 93% of patients were satisfied with their operation. History of prior realignment surgery was associated with significantly worse outcomes compared to patients where MPFL reconstruction was their first realignment procedure (p < 0.05). This series is the largest reported in the literature for any technique of MPFL surgery. This technique allows for objective intra-operative evaluation of the required graft tension to optimise patella tracking

Purpose. To assess the midterm functional results after Medial Patellofemoral Ligament (MPFL) reconstruction with single semitendinosis autograft in patients with patellofemoral instability. Methods - Results. Forty six knees (45 patients) with patellofemoral instability were treated with surgical stabilisation of the patella with a single semitendinosis autograft and followed up for a minimum of 24 months. The average follow-up was 33.5 months (range 24-54 months). Clinical evidence of patellar instability and radiological (MRI) evidence of MPFL rupture or deficiency was documented prior to surgery. The average post injury interval was 22.3 months. Ipsilateral joint co-morbidities included previous lateral release or distal realignment (n=10), patellofemoral joint (PFJ) dysplasia (n=14) and concurrent ACL, PCL and/or MCL rupture (n=6). Knee function was assessed preoperatively and postoperatively with the use of Kujala, Tegner, Lysholm and International Knee Documentation Committee (IKDC) scores. There were 34 male and 11 female patients with a mean age of 32.5 years (range 17 - 60 years). All measured knee function scores improved postoperatively. Kujala score improved from 58 to 77 (95%CI +/− 9.71). Tegner score improved from 3 to 5 (95%CI+/− 0.65). IKDC score improved from 51 to 75 (95%CI +/− 5.27) and Lysholm score improved from 59 to 79 (95%CI +/− 6.5). Conclusions. MPFL reconstruction with semitendinosis autograft is an effective treatment at a minimum of 24 months (midterm) follow-up in patients with patellofemoral instability even in the presence of heterogeneous knee co-morbidities such as PFJ dysplasia, previous lateral release and failed realignment surgery

Proximal femoral deformity is common in children with cerebral palsy (CP), contributing to hip instability and ambulation difficulties. This population-based cohort study investigates the prevalence and significance of these deformities in relation to Gross Motor Function Classification System (GMFCS) level. Children with a confirmed diagnosis of CP born within a three-year period were identified from a statewide register. Motor type, topographical distribution and GMFCS level were obtained from clinical notes. Neck Shaft Angle (NSA) and Migration Percentage (MP) were measured from an anteroposterior pelvis x-ray with the hips internally rotated. Measurement of FNA was by the Trochanteric Palpation Test (TPAT) or during fluoroscopic screening of the hip with a guide wire in the centre of the femoral neck. Linear regression analysis was performed for FNA, NSA and MP according to GMFCS level. 292 children were eligible. FNA was increased in all GMFCS levels. The lowest measurements were at GMFCS levels I and II p<0.001. GMFCS levels III, IV, and V were uniformly high p<0.001. Neck shaft angle increased sequentially from GMFCS levels I to V (p<0.001). This study confirms a very high prevalence of increased FNA in children with CP in all GMFCS levels. In contrast, NSA and MP progressed step-wise with GMFCS level. We propose that increased FNA in children with CP represents failure to remodel normal fetal alignment because of delay in ambulation and muscle imbalance across the hip joint. In contrast, coxa valga is an acquired deformity and is largely related to lack of weight bearing and functional ambulation. The high prevalence of both deformities at GMFCS levels IV and V explain the high rate of displacement in these hips and the need for proximal femoral realignment surgery in the prevention and management of hip displacement

Aims

The aim of this study was to inform the epidemiology and treatment of slipped capital femoral epiphysis (SCFE).

Certain cases of patello-femoral maltracking can lead to articular surface wear. Though most can be treated non-operatively, where there is increasing wear surgical intervention may be necessary. Patellar tracking is difficult to assess and though several different types of maltracking or loading have been described, each case warrants precise assessment of the wear patterns. Without this knowledge a logical approach to realignment surgery is impossible. 60 consecutive cases (age range 18–50 years) presenting with anterior knee pain were arthroscoped over a 4 year period. These patients all had been selected with either patellar instability or surface wear indicated either clinically, a positive radiograph, bone scan or MRI. All patients were arthroscoped through standard anterolateral and antero-medial portals and also a superolateral and occasionally a supero-medial approach. The areas of articular damage were mapped on diagrams and recorded photographically. Patella views were taken in flexion and extension, and on passively stretching the patella medially and laterally. We found 6 distinct patterns of wear which appear to indicate 6 different maltracking abnormalities. The largest group, 46 patients, consisted of lateral trackers, with 21 patients demonstrating medial facet and lateral femoral condylar wear. Assessment of the articular surface of the patello-femoral groove from inferior portals is highly misleading and superior portals are needed for proper assessment. Medial facet wear can occur in lateral instability or medial compression. Lateral maltracking at engagement or distally are the commonest patterns

Purpose: Reconstruction of massive bone loss with cancellous bone deposited in a pseudomembrane induced by a cemented strut was performed in 40 procedures. We evaluated the 5-year results of this technique for the treatment of gaps measuring more than 5 cm. Material and methods: We reviewed 12 patients; all had suffered major loss of tibial bone. The operations consisted in resection, insertion of a cement strut, and closure with a local are free flap over he disinfected soft tissues. The second operation at least two years later used a fragmented autologous cancellous graft leaving the membrane intact. The fibula was used as a tutor whenever possible. Bone losses measured 5 to 25 cm in young men who had infection after trauma or, in one patient, tumour resection. We analysed clinical and radiological outcome. Results: All patients were seen five to ten years after initial management. At last follow-up, all wounds had dried and bone healing was solid. All had required secondary repeated grafts, realignment surgery (for valgus and varus) or operations related to the initial injury (arthrodesis, claw toe). Generally, the patients had resumed their occupational and recreational activities. The walking distance was not limited and single leg stance was painless. The radiological analysis demonstrated a trend towards graft tubulisation. Discussion: The stut technique using cement induces the formation of a pseudo-synovial membrane. This technique has been used for more than ten years in our unit to treat circumferential defects. Bone healing was achieved in all patients. The main complication was valgus malalignment which almost always requires surgical correction. Rapid healing is not a function of the extent of the gap but rather the radical nature of the resection and the quality of the cover. This technique should be compared with other alternatives used to fill major bone gaps (Illizarov, vascularised bone transfer)

Purpose: Since the pathomechanism of patellofemoral malalignment is complex, multifactorial and varies individually, the ideal treatment has been a matter of controversy. The purpose of this study was to demonstrate the clinical outcome and radiographic changes of knees with patellofemoral malalignment treated with Fulkerson osteotomy after a minimum follow-up of 24 months. Materials and Methods: Sixty knees in 40 patients (32 female and 8 male) were examined with a mean of 55 20 (25 97) months after having undergone medialization of the tibial tubercle using Fulkerson osteotomy for patel-lofemoral malalignment. Mean age at surgery was 20 7 (12 42) years. Prior surgery of medial retinacular plication in 4 knees and lateral retinacular release in 1 knee had been performed. During surgery, amount of tibial tubercle transfer was determined by examining the patellar tracking over full range of knee motion. After Fulkerson osteotomy, proximal realignment procedures were added depending on arthroscopic appearance of the patellofemoral adaptation. The clinical outcome was evaluated using Fulkersons knee instability scale. The radiographic parameters including congruence angle, lateral patellofemoral angle, tilting angle and lateral shift ratio were measured in Merchant view. Results: Mean distance of medial transfer of tibial tubercle was 12.8 3.1 (8 22) mm. Lateral retinacular release in 54 knees and adductor magnus tenodesis (Avikainen procedure) in 2 knees were simultaneously performed combined with Fulkerson osteotomy. All radiographic parameters at the final follow-up were significantly improved compared to the preoperative values (p < 0.05 in a paired t-test), that is, from 23.0 14.6 to 0.4 13.7 degrees in congruence angle, from −6.3 9.0 to 0.4 6.9 degrees in lateral patellofemoral angle, from 25.1 11.5 to 16.3 5.6 degrees in tilting angle and from 35 24 to 17 9% in lateral shift ratio. Mean score in Fulkersons knee instability scale was 96 5 points at the final follow-up. All knees except 3 were ranked as excellent, very good or good. Two knees with moderate osteoarthritis of the patellofemoral joint were ranked as fair. One knee that had postoperative recurrence of patellar subluxation underwent a revision surgery with Avikainen procedure. Discussion: In the clinical study with a minimum 2-year follow-up, Fulkerson tibial tubercle osteotomy provided excellent or good overall outcome in 93% of patients in combination with proximal realignment surgeries. Although all radiographic parameters were significantly improved, it was found that the lateral shift of the patella was more effectively corrected compared to the lateral tilt. It was suggested that reconstruction of the medial patellofemoral structures might be more suitable than Fulkerson osteotomy for some knees characterized by significant lateral tilt

The October 2013 Knee Roundup³⁶⁰ looks at: Make it easy, release the MCL; Do patients remember clinical information in day surgery?; Osteoarthritis and arthroscopy?; How best to double your bundles; When to operate for infection; Cementless unicompartment knee replacement?; Tibial tubercle-trochlear groove confusion; Tarts, cherries and osteoarthritis