Aims

While residual fixed flexion deformity (FFD) in unicompartmental knee arthroplasty (UKA) has been associated with worse functional outcomes, limited evidence exists regarding FFD changes. The objective of this study was to quantify FFD changes in patients with medial unicompartmental knee arthritis undergoing UKA, and investigate any correlation with clinical outcomes.

Advanced 3D imaging and CT-based navigation have emerged as valuable tools to use in total knee arthroplasty (TKA), for both preoperative planning and the intraoperative execution of different philosophies of alignment. Preoperative planning using CT-based 3D imaging enables more accurate prediction of the size of components, enhancing surgical workflow and optimizing the precision of the positioning of components. Surgeons can assess alignment, osteophytes, and arthritic changes better. These scans provide improved insights into the patellofemoral joint and facilitate tibial sizing and the evaluation of implant-bone contact area in cementless TKA. Preoperative CT imaging is also required for the development of patient-specific instrumentation cutting guides, aiming to reduce intraoperative blood loss and improve the surgical technique in complex cases. Intraoperative CT-based navigation and haptic guidance facilitates precise execution of the preoperative plan, aiming for optimal positioning of the components and accurate alignment, as determined by the surgeon’s philosophy. It also helps reduce iatrogenic injury to the periarticular soft-tissue structures with subsequent reduction in the local and systemic inflammatory response, enhancing early outcomes. Despite the increased costs and radiation exposure associated with CT-based navigation, these many benefits have facilitated the adoption of imaged based robotic surgery into routine practice. Further research on ultra-low-dose CT scans and exploration of the possible translation of the use of 3D imaging into improved clinical outcomes are required to justify its broader implementation. Cite this article: Bone Joint J 2024;106-B(9):892–897

The August 2024 Trauma Roundup³⁶⁰ looks at: Does topical vancomycin prevent fracture-related infections in closed fractures undergoing open reduction and internal fixation? A randomized controlled trial; Is postoperative splinting advantageous after upper limb fracture surgery?; Does suprapatellar nailing resolve knee pain?; Locking versus non-locking plate fixation in comminuted talar neck fractures: a biomechanical study using cadaveric specimens; Revolutionizing recovery metrics: PROMIS versus SMFA in orthopaedic trauma care; Dorsal hook plating of patella fractures: reliable fixation and satisfactory outcomes; The impact of obesity on subtrochanteric femur fracture outcomes; Low-dose NSAIDs (ketorolac) and cytokine modulation in orthopaedic polytrauma: a detailed analysis.

Aims

This study aimed to evaluate if total knee arthroplasty (TKA) femoral components aligned in either mechanical alignment (MA) or kinematic alignment (KA) are more biomimetic concerning trochlear sulcus orientation and restoration of trochlear height.

Aims

Robotic arm-assisted surgery offers accurate and reproducible guidance in component positioning and assessment of soft-tissue tensioning during knee arthroplasty, but the feasibility and early outcomes when using this technology for revision surgery remain unknown. The objective of this study was to compare the outcomes of robotic arm-assisted revision of unicompartmental knee arthroplasty (UKA) to total knee arthroplasty (TKA) versus primary robotic arm-assisted TKA at short-term follow-up.

Aims

This study aims to determine the rate of and risk factors for total knee arthroplasty (TKA) after operative management of tibial plateau fractures (TPFs) in older adults.

Aims. With up to 40% of patients having patellofemoral joint osteoarthritis (PFJ OA), the two arthroplasty options are to replace solely the patellofemoral joint via patellofemoral arthroplasty (PFA), or the entire knee via total knee arthroplasty (TKA). The aim of this study was to assess postoperative success of second-generation PFAs compared to TKAs for patients treated for PFJ OA using patient-reported outcome measures (PROMs) and domains deemed important by patients following a patient and public involvement meeting. Methods. MEDLINE, EMBASE via OVID, CINAHL, and EBSCO were searched from inception to January 2022. Any study addressing surgical treatment of primary patellofemoral joint OA using second generation PFA and TKA in patients aged above 18 years with follow-up data of 30 days were included. Studies relating to OA secondary to trauma were excluded. ROB-2 and ROBINS-I bias tools were used. Results. A total of nine studies were included, made up of four randomized controlled trials (domain 1) and five cohort studies (domain 2). PROMs and knee function specific scores developed for reporting TKA were unable to detect any difference between PFA and TKA. There was no significant difference in complications between PFA and TKA. PFAs were found to have a better postoperative range of motion. Conclusion. TKA and PFA are both viable options for patients with primary PFJ OA. Over time, we have seen an emphasis on patient satisfaction and better quality of life. Recommending sacrificing healthy medial and lateral compartments to treat patellofemoral joint arthritis should be given further thought. Cite this article: Bone Jt Open 2023;4(12):948–956

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The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.

Aims

The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Abstract. Objectives. The aim of this study was to develop an in vitro GAG-depleted patella model and assess the biomechanical effects following treatment with a SAP:CS self-assembling hydrogel. Methods. Porcine patellae (4–6 month old) were harvested and subject to 0.1% (w/v) sodium dodecyl sulfate (SDS) washes to remove GAGs from the cartilage. Patellae were GAG depleted and then treated by injection with SAP (∼ 6 mM) and CS (10 mg) in Ringer's solution through a 30G needle. Native, GAG depleted and SAP:CS treated patellae were tested through static indentation testing, using 15g load, 5mm indenter over 1hr period. The degree of deformation of each group was assessed and compared (Mann-Whitney, p<0.05). Native, GAG depleted, sham (saline only) and SAP:CS treated paired patellae and femurs were additionally characterized tribologically through sequential wear testing when undergoing a walking gait profile (n=6 per group). The cartilage surfaces were assessed and compared (Mann-Whitney, p<0.05) using the ICRS scoring system, surface damage was illustrated through the application of Indian ink. Results. Static indentation tests indicated significant increase in indentation deformation of GAG depleted group compared to native group (n=6, p<0.01) and significant reduction in deformation of SAP:CS treated group compared to GAG depleted group (n=6, p<0.05). Sequential wear tests indicated a significant increase in the cartilage damage on the both surfaces of the patellofemoral joint in the GAG depleted group, compared to the native group (n=6, p<0.001), Following SAP:CS treatment, significant protection from damage was observed on femoral surface (n=6, p<0.005), with some non-significant reduction in damage on the patella surface. Sham injections showed no significant increase in damage compared to the native and treated samples. Conclusions. The ∼50% reduction of GAGs represented a moderate osteoarthritic patella cartilage model. This same loss transferred to the dynamic wear tests with significant changes in the damage on the femoral counter face associated with the GAG loss. SAP:CS treatment showed promise in restoring cartilage stiffness to treat Chondromalacia patella in static indentation tests. Sequential wear tests showed that the SAP:CS treatment protects the cartilage layer of both surfaces in the patellofemoral joint from damage in an extreme degeneration model. The sham injections showed that injecting cartilage with a 30G and saline does not cause any significant damage to the cartilage layer. Declaration of Interest. (a) fully declare any financial or other potential conflict of interest

Aims

This prospective study reports longitudinal, within-patient, patient-reported outcome measures (PROMs) over a 15-year period following cemented single radius total knee arthroplasty (TKA). Secondary aims included reporting PROMs trajectory, 15-year implant survival, and patient attrition from follow-up.

Abstract. INTRODUCTION. 10% of patients with knee osteoarthritis (OA) have disease confined to the patellofemoral joint (PFJ). The main surgical options are total knee replacement (TKR) and PFJ replacement (PFJR). PFJR has advantages over TKR, including being less invasive, bone preserving, allowing faster recovery and better function and more ‘straight forward’ revision surgery. We aim to compare the clinical results of revised PFJR with primary TKR taking into consideration the survival length of the PFJR. METHODOLOGY. Twenty-five patients (21 female) were retrospectively identified from our arthroplasty database who had undergone revision from PFJR to TKR (2006–2019). These patients were then matched with regards to their age at their primary procedure, sex and total arthroplasty life (primary PFJ survival + Revision PFJ time to follow up) up to point of follow-up with a group of primary TKRs implanted at the same point as the primary PFJR. RESULTS. Mean survival of the PFJs revised were 4.2 years. In the PFJR revision group (mean arthroplasty life 7.8 years) mean Oxford knee score (OKS) at latest follow up was 27.8. In the primary knee group (mean arthroplasty life 7.5 years) mean OKS was 32.4. This difference was not statistically significant. All PFJR revisions were performed using primary prostheses. CONCLUSION. PFJR provides comparable clinical outcome even after revision surgery to TKR as primary TKRs at midterm follow up and should be considered in all patients meeting the selection criteria. Given comparable proms and straight forward revisions, staged arthroplasty to preserve bone-stock is a reasonable choice

Abstract. Introduction. Isolated patellofemoral osteoarthritis accounts for 10% of knee osteoarthritis. Many of these will not require arthroplasty solutions, but for those who are sufficiently symptomatic, patellofemoral joint (PFJ) replacement has been shown to be an effective procedure. The National Joint Registry (NJR) has shown a higher revision rate for this operation, particularly in younger patients (males <55 years 13.3% failure at 5 years, females 9.6%). The aim of this study is to report on the medium-term outcome of the Avon patellofemoral joint arthroplasty in patients under 55 from a non-design centre. There is no other published case series on this young patient cohort. Methodology. 50 Avon PFJ replacements (Stryker, Kalamazoo USA) were undertaken in 46 patients under 55 years old (range 35 – 54, mean 48.8) between 2010 and 2022 for end-stage isolated PFJ arthritis shown on Xray and MRI scan. The outcome measure was all-cause revision rate. This was assessed by review of clinical notes, imaging and NJR data. Results. The mean follow up was 5.8 years (range 6 months to 12.9 years). Only one patient had a revision procedure (for progressive osteoarthritis) which was 3 years after the primary procedure. This patient has had no further surgery. The implant survival rate was 97.2% at 5 years and 97.2% at 10 years. Conclusion. This study shows that patellofemoral joint replacement with the Avon prosthesis can give a satisfactory revision rate in the medium term in patients under 55 if carefully selected

Abstract. Introduction. Isolated patellofemoral joint(PFJ) osteoarthritis affects approximately 10% of patients aged over 40 years and treatment remains controversial. Our aim was to evaluate long term functional and radiological outcomes following PFJ arthorplasty with the Femoro Patella Vialli (FPV) prosthesis as this evidence is lacking in literature. Methodology. A retrospective review of prospectively collected PROMS in patients undergoing Patellofemoral arthroplasty. Single centre trial. Between 2004 and 2008, 101 FPV patellofemoral arthroplasties were performed in 80 patients with isolated patellofemoral joint osteoarthritis. Data was collected as a part of routine follow-up for up to 6 years and additional long term data was collected at 16 years. Results. At 6 year follow up the mean OKS was 29 and by 16 year follow up it was 26 which was not a statistically significant drop. 22 patients (29 knees) had died, 32 (32%) had been revised, 25 to total knee replacement using primary arthroplasty components. Mean OKS in the revised group was 27 which was not a statistically significant difference when compared to the unrevised group. Mean time to revision was 4 years. The cumulative survival analysis of the FPV implant was 76% at 5 years, 64% at 10 years. Conclusion. Our findings suggest the FPV patellofemoral prosthesis provides good pain relief and clinical outcomes however, the survivorship for this particular implant maybe lower as compared to the available literature. Patient reported outcomes are maintained over the implant life and are no worse once revised implying a staged approach to arthroplasty is reasonable

Aims. Classifying trochlear dysplasia (TD) is useful to determine the treatment options for patients suffering from patellofemoral instability (PFI). There is no consensus on which classification system is more reliable and reproducible for the purpose of guiding clinicians’ management of PFI. There are also concerns about the validity of the Dejour Classification (DJC), which is the most widely used classification for TD, having only a fair reliability score. The Oswestry-Bristol Classification (OBC) is a recently proposed system of classification of TD, and the authors report a fair-to-good interobserver agreement and good-to-excellent intraobserver agreement in the assessment of TD. The aim of this study was to compare the reliability and reproducibility of these two classifications. Methods. In all, six assessors (four consultants and two registrars) independently evaluated 100 axial MRIs of the patellofemoral joint (PFJ) for TD and classified them according to OBC and DJC. These assessments were again repeated by all raters after four weeks. The inter- and intraobserver reliability scores were calculated using Cohen’s kappa and Cronbach’s α. Results. Both classifications showed good to excellent interobserver reliability with high α scores. The OBC classification showed a substantial intraobserver agreement (mean kappa 0.628; p < 0.005) whereas the DJC showed a moderate agreement (mean kappa 0.572; p < 0.005). There was no significant difference in the kappa values when comparing the assessments by consultants with those by registrars, in either classification system. Conclusion. This large study from a non-founding institute shows both classification systems to be reliable for classifying TD based on axial MRIs of the PFJ, with the simple-to-use OBC having a higher intraobserver reliability score than that of the DJC. Cite this article: Bone Jt Open 2023;4(7):532–538

Aims

This systematic review and meta-analysis aimed to compare the influence of patellar resurfacing following cruciate-retaining (CR) and posterior-stabilized (PS) total knee arthroplasty (TKA) on the incidence of anterior knee pain, knee-specific patient-reported outcome measures, complication rates, and reoperation rates.

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To assess the incidence of radiological lateral osteoarthritis (OA) at 15 years after medial unicompartmental knee arthroplasty (UKA) and assess the relationship of lateral OA with symptoms and patient characteristics.

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Unicompartmental knee arthroplasty (UKA) has higher revision rates than total knee arthroplasty (TKA). As revision of UKA may be less technically demanding than revision TKA, UKA patients with poor functional outcomes may be more likely to be offered revision than TKA patients with similar outcomes. The aim of this study was to compare clinical thresholds for revisions between TKA and UKA using revision incidence and patient-reported outcomes, in a large, matched cohort at early, mid-, and late-term follow-up.